Compounds which potentiate glutamate receptor and uses thereof in medicine

ABSTRACT

Compounds of formula (I) or a pharmaceutically acceptable salt, solvate or prodrug thereof, are disclosed: 
                         
wherein R 1  is C 1-6 alkyl, haloC 1-6 alkyl, C 2-6 alkenyl, amino, monoC 1-4 alkylamino or diC 1-4 alkylamino; R 2  and R 3 , which may be the same or different, are hydrogen, halogen, C 1-6 alkyl, haloC 1-6 alkyl, C 1-4 alkoxy, haloC 1-4 alkoxy, cyano, amino, monoC 1-4 alkylamino or diC 1-4 alkylamino; each R 4 , which may be the same or different, is C 1-6 alkyl, halogen, C 1-6 alkyl, haloC 1-6 alkyl, C 1-4 alkoxy, haloC 1-4 alkoxy, cyano, nitro, amino, monoC 1-4 alkylamino or diC 1-4 alkylamino; p is 0, 1 or 2; n is 1 or 2; R 5  and R 6 , which may be the same or different, are hydrogen, halogen, C 1-6 alkyl, haloC 1-6 alkyl, C 1-4 alkoxy, haloC 1-4 alkoxy, cyano, amino, monoC 1-4 alkylamino or diC 1-4 alkylamino; and Het is thienyl, pyridyl, pyrimidinyl, pyridazinyl, pyrimidinyl, pyrazinyl, imidazolyl, pyrazolyl, pyrrolyl, quinolyl, thiazolyl or furyl, each of which may be substituted by one or more groups independently selected from the list consisting of C 1-6 alkyl, C 1-6 alkoxy, acetyl, halogen, haloC 1-6 alkyl, cyano, nitro, amino, monoC 1-4 alkylamino and diC 1-4 alkylamino. Methods of preparation of the compounds, and uses thereof in medicine, for example treatment of schizophrenia, are also disclosed.

This application claims the benefit of International Application No.PCT/EP2005/008562, filed 5 Aug. 2005, which claims the priority ofGB0417708.5 filed 9 Aug. 2004 and GB 0508473.6 filed Apr. 26, 2005.

This invention relates to novel compounds which potentiate the glutamatereceptor. The invention also relates to the use of the derivatives intreating diseases and conditions mediated by potentiation of theglutamate receptor, compositions containing the derivatives andprocesses for their preparation.

Glutamate receptors, which mediate the majority of fast excitatoryneurotransmission in the mammalian central nervous system (CNS), areactivated by the excitatory amino acid, L-glutamate (for review seeWatkins J C, Krogsgaard-Larsen P, Honore T (1990) Trends Pharmacol Sci11: 25-33).

Glutamate receptors can be divided into two distinct families. TheG-protein or second messenger-linked “metabotropic” glutamate receptorfamily which can be subdivided into three groups (Group I, mGlu1 andmGlu5; Group II, mGlu2 and mGlu3; Group III, mGlu4, mGlu6, mGlu7, mGlu8)based on sequence homology and intracellular transduction mechanisms(for review see Conn P J and Pinn J P (1997) Ann Rev Pharmacol Toxicol37: 205-237). The “ionotropic” glutamate receptor family, which directlycouple to ligand-gated cation channels, can be subdivided into at leastthree subtypes based on depolarizing activation by selective agonists,N-methyl-D-aspartate (NMDA),α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA) and kainicacid (KA) (for review see Dingledine R, Borges K, Bowie, Traynelis S(1999) 51: 7-61).

Native AMPA receptors (AMPAR) exist as heterotetramers consisting ofcombinations of four different protein subunits (GluR1-4) (for reviewsee Bettler B and Muller C (1995) 34: 123-139.). Receptor subunitdiversity is increased further as each subunit can undergo alternativesplicing of a 38 amino acid sequence in the extracellular region justbefore the fourth membrane spanning domain M4. Such editing results inso-called ‘flip’ and ‘flop’ receptor isoforms which differ in kineticand pharmacological properties (Sommer B, Keinanen K, Verdoon T A,Wisden W, Burnashev N, Herb A, Kohler M, Takagi T, Sakmann B, Seeburg PH (1990) Science 249: 1580-1585).

Additionally, post-transcriptional editing of GluR2 mRNA changes aneutral glutamine to a positively charged arginine within M2. In normalhumans >99% GluR2 is edited in this way. AMPAR containing such editedGluR2 subunit exhibit low calcium permeability (Burnachev N, Monyer H,Seeburg P H, Sakmann B (1992) Neuron 8: 189-198). There is a suggestion,however, that the number of AMPAR with high calcium permeability iselevated in certain disease-associated conditions (Weiss J H, and SensiS L (2000) Trends in Neurosci 23: 365-371.

AMPAR depolarization removes voltage dependent Mg2+ block of NMDAreceptors which in turn leads to NMDA receptor activation, an integralstage in the induction of Long Term Potentiation (Bliss T V P,Collingridge G L (1993) Nature 361: 31-9). Long Term Potentiation is aphysiological measure of increased synaptic strength following arepetitive stimulus or activity, such as occurs during learning.

Direct activation of glutamate receptors by agonists, in conditionswhere glutamate receptor function is reduced, increases the risk ofexcitotoxicity and additional neuronal damage. AMPAR positive allostericmodulators, alone, do not activate the receptor directly. However, whenthe ligand (L-glutamate or AMPA) is present AMPAR modulators increasereceptor activity. Thus, AMPA receptor modulators only enhance synapticfunction when glutamate is released and is able to bind at post-synapticreceptor sites.

Compounds which act as AMPAR positive allosteric modulators have beenshown to increase ligand affinity for the receptor (Arai A, Guidotti A,Costa E, Lynch G (1996) Neuroreport. 7: 2211-5.); reduce receptordesensitization and reduce receptor deactivation (Arai A C, Kessler M,Rogers G, Lynch G (2000) 58: 802-813) and facilitate the induction ofLTP both in vitro (Arai A, Guidotti A, Costa E, Lynch G (1996) 7:2211-5.) and in vivo (Staubli U, Perez Y, Xu F, Rogers G, Ingvar M,Stone-Elander S, Lynch G (1994) Proc Natl Acad Sci 91: 11158-11162).Such compounds also enhance the learning and performance of variouscognitive tasks in rodent (Zivkovic I, Thompson D M, Bertolino M, UzunovD, DiBella M, Costa E, Guidotti A (1995) JPET 272: 300-309, Lebrun C,Pilliere E, Lestage P (2000) Eu J Pharmacol 401: 205-212), sub-humanprimate (Thompson D M, Guidotti A, DiBella M, Costa E (1995) Proc NatlAcad Sci 92: 7667-7671) and man (Ingvar M, Ambros-Ingerson J, Davis M,Granger R, Kessler M, Rogers G A, Schehr R S, Lynch G (1997) Exp Neurol146: 553-559).

It is envisaged that compounds that modulate glutamate receptor functionmay be useful in treating the following conditions and diseases:psychosis and psychotic disorders (including schizophrenia,schizo-affective disorder, schizophreniform diseases, brief reactivepsychosis, child onset schizophrenia, “schizophrenia-spectrum” disorderssuch as schizoid or schizotypal personality disorders, acute psychosis,alcohol psychosis, drug-induced psychosis, autism, delerium, mania(including acute mania), manic depressive psychosis, hallucination,endogenous psychosis, organic psychosyndrome, paranoid and delusionaldisorders, puerperal psychosis, and psychosis associated withneurodegenerative diseases such as Alzheimer's disease); cognitiveimpairment (e.g. the treatment of impairment of cognitive functionsincluding attention, orientation, memory (i.e. memory disorders,amnesia, amnesic disorders and age-associated memory impairment) andlanguage function, and including cognitive impairment as a result ofstroke, Alzheimer's disease, Aids-related dementia or other dementiastates, as well as other acute or sub-acute conditions that may causecognitive decline such as delirium or depression (pseudodementia states)trauma, aging, stroke, neurodegeneration, drug-induced states,neurotoxic agents), mild cognitive impairment, age related cognitiveimpairment, autism related cognitive impairment, Down's syndrome,cognitive deficit related to psychosis, post-electroconvulsive treatmentrelated cognitive disorders; anxiety disorders (including generalisedanxiety disorder, social anxiety disorder, agitation, tension, social oremotional withdrawal in psychotic patients, panic disorder, andobsessive compulsive disorder); neurodegenerative diseases (such asAlzheimer's disease, amyotrophic lateral sclerosis, motor neuronedisease and other motor disorders such as Parkinson's disease (includingrelief from locomotor deficits and/or motor disability, including slowlyincreasing disability in purposeful movement, tremors, bradykinesia,hyperkinesia (moderate and severe), akinesia, rigidity, disturbance ofbalance and co-ordination, and a disturbance of posture), dementia inParkinson's disease, dementia in Huntington's disease,neuroleptic-induced Parkinsonism and tardive dyskinesias,neurodegeneration following stroke, cardiac arrest, pulmonary bypass,traumatic brain injury, spinal cord injury or the like, anddemyelinating diseases such as multiple sclerosis and amyotrophiclateral sclerosis); depression (which term includes bipolar (manic)depression (including type I and type II), unipolar depression, singleor recurrent major depressive episodes with or without psychoticfeatures, catatonic features, melancholic features, atypical features(e.g. lethargy, over-eating/obesity, hypersomnia) or postpartum onset,seasonal affective disorder and dysthymia, depression-related anxiety,psychotic depression, and depressive disorders resulting from a generalmedical condition including, but not limited to, myocardial infarction,diabetes, miscarriage or abortion); post-traumatic stress syndrome;attention deficit disorder; attention deficit hyperactivity disorder;drug-induced (phencyclidine, ketamine and other dissociativeanaesthetics, amphetamine and other psychostimulants and cocaine)disorders; Huntington's chorea; tardive dyskinesia; dystonia; myoclonus;spasticity; obesity; stroke; sexual dysfunction; and sleep disorders. Inaddition, it is envisaged that compounds that modulate glutamatereceptor function may be useful in treating non-impaired subjects forenhancing performance in sensory-motor and cognitive tasks and memoryencoding.

We have discovered a class of novel compounds that potentiate theglutamate receptor.

According to a first aspect, the invention provides a compound offormula (I), a pharmaceutically acceptable salt, solvate or prodrugthereof:

wherein:

-   -   R¹ is C₁₋₆alkyl, haloC₁₋₆alkyl, C₂₋₆alkenyl, amino,        monoC₁₋₄alkylamino or diC₁₋₄alkylamino;    -   R² and R³, which may be the same or different, are hydrogen,        halogen, C₁₋₆alkyl, haloC₁₋₆alkyl, C₁₋₄alkoxy, haloC₁₋₄alkoxy,        cyano, amino, monoC₁₋₄alkylamino or diC₁₋₄alkylamino;    -   each R⁴, which may be the same or different, is C₁₋₆alkyl,        halogen, C₁₋₆alkyl, haloC₁₋₆alkyl, C₁₋₄alkoxy, haloC₁₋₄alkoxy,        cyano, nitro, amino, monoC₁₋₄alkylamino or diC₁₋₄alkylamino;    -   p is 0, 1 or 2;    -   n is 1 or 2;    -   R⁵ and R⁶, which may be the same or different, are hydrogen,        halogen, C₁₋₆alkyl, haloC₁₋₆alkyl, C₁₋₄alkoxy, haloC₁₋₄alkoxy,        cyano, amino, monoC₁₋₄alkylamino or diC₁₋₄alkylamino; and    -   Het is thienyl, pyridyl, pyrimidinyl, pyridazinyl, pyrazinyl,        imidazolyl, pyrazolyl, pyrrolyl, quinolyl, thiazolyl or furyl,        each of which may be substituted by one or more groups        independently selected from the list consisting of C₁₋₆alkyl,        C₁₋₆alkoxy, acetyl, halogen, haloC₁₋₆alkyl, cyano, nitro, amino,        monoC₁₋₄alkylamino and diC₁₋₄alkylamino.

The term “C₁₋₄alkyl” refers to an alkyl group having from one to fourcarbon atoms, in all isomeric forms, such as methyl, ethyl, propyl,isopropyl, butyl, isobutyl, sec-butyl and tert-butyl. The term“C₁₋₆alkyl” refers to an alkyl group having from one to six carbonatoms, in all isomeric forms, such as methyl, ethyl, propyl, isopropyl,butyl, isobutyl, sec-butyl, tert-butyl, pentyl, neopentyl, sec-pentyl,n-pentyl, isopentyl, tert-pentyl and hexyl. Unless otherwise indicated,any alkyl group may be straight or branched and is of 1 to 6 carbonatoms, such as 1 to 4 or 1 to 3 carbon atoms.

The term “halo” refers to fluoro, chloro, bromo or iodo.

The term “haloC₁₋₆alkyl” refers to a C₁₋₆alkyl group wherein at leastone hydrogen atom is replaced with halogen. Examples of such groupsinclude fluoroethyl, trifluoromethyl or trifluoroethyl and the like.

The term “C₂₋₆alkenyl” refers to a straight or branched hydrocarbongroup containing one or more carbon-carbon double bonds and having from2 to 6 carbon atoms. Unless otherwise indicated, a C₂₋₆alkenyl group maycontain up to 3 double bonds which may be conjugated. Examples of suchgroups include ethenyl, propenyl, butenyl, pentenyl, hexenyl, vinyl,allyl and butadienyl.

The term “monoC₁₋₄alkylamino” refers to an amino group substituted by aC₁₋₄alkyl group, such as methylamino, ethylamino, propylamino orbutylamino. The term “diC₁₋₄alkylamino” refers to an amino groupsubstituted by two C₁₋₄alkyl groups, such as dimethylamino ormethylethylamino.

The term “C₁₋₄alkoxy” refers to an —OC₁₋₄alkyl group wherein C₁₋₄alkylis as defined herein. The term “C₁₋₆alkoxy” as used herein refers to an—OC₁₋₆alkyl group wherein C₁₋₆alkyl is as defined herein. Examples ofC₁₋₄alkoxy groups include methoxy, ethoxy, propoxy and butoxy. Examplesof C₁₋₆alkoxy groups include, in addition, pentoxy and hexoxy and thelike.

The term “halo C₁₋₆alkoxy” as used herein refers to a C₁₋₆alkoxy groupas herein defined wherein at least one hydrogen atom is replaced withhalogen. Examples of such groups include difluoromethoxy ortrifluoromethoxy and the like.

In one embodiment, R¹ is C₁₋₆alkyl such as isopropyl.

In one embodiment, R² and R³, which may be the same or different, arehydrogen, halogen or C₁₋₆alkyl, for example hydrogen, fluorine ormethyl.

In one embodiment, p is 0.

In one embodiment, each R⁴, which may be the same or different, isC₁₋₆alkyl or halogen, for example methyl or fluorine.

In one embodiment, R⁵ and R⁶, which may be the same or different, arehydrogen, halogen or C₁₋₆alkyl. For example R⁵ and R⁶ are independentlyhydrogen, fluorine or methyl.

In one embodiment, n is 1.

In one embodiment, Het is pyridyl (eg 3-pyridyl), pyrimidinyl (eg5-pyrimidinyl, 2-pyrimidinyl), thienyl (eg 3-thienyl, 2-thienyl),pyridazinyl (eg 3-pyridazinyl), imidazolyl (eg 1H-4-imidazolyl) orpyrazolyl (eg 1H-4-pyrazolyl), each of which is optionally substitutedby one to three groups independently selected from the group consistingof C₁₋₆alkyl (such as methyl), acetyl, cyano, halogen (such as fluorineor chlorine), haloC₁₋₆alkyl (such as CF₃) and C₁₋₆alkoxy (such asmethoxy).

In one embodiment, the present invention provides a compound of formula(Ia), a pharmaceutically acceptable salt, solvate or prodrug thereof:

wherein Het and R¹ are as defined for formula (I).

For the avoidance of doubt, unless otherwise indicated, the term“substituted” means substituted by one or more defined groups. In thecase where groups may be selected from a number of alternative groups,the selected groups may be the same or different. For the avoidance ofdoubt, the term “independently” means that where more than onesubstituent is selected from a number of possible substituents, thosesubstituents may be the same or different.

Suitable pharmaceutically acceptable salts of the compounds of formula(I) include acid salts, for example sodium, potassium, calcium,magnesium and tetraalkylammonium and the like, or mono- or di- basicsalts with the appropriate acid for example organic carboxylic acidssuch as formic, acetic, lactic, tartaric, malic, isethionic, lactobionicand succinic acids; organic sulfonic acids such as methanesulfonic,ethanesulfonic, benzenesulfonic and p-toluenesulfonic acids andinorganic acids such as hydrochloric, sulfuric, phosphoric and sulfamicacids and the like. Some of the compounds of this invention may becrystallised or recrystallised from solvents such as aqueous and organicsolvents. In such cases solvates may be formed. This invention includeswithin its scope stoichiometric solvates including hydrates as well ascompounds containing variable amounts of water that may be produced byprocesses such as lyophilisation.

It will be appreciated by those skilled in the art that certainprotected derivatives of compounds of formula (I), which may be madeprior to a final deprotection stage, may not possess pharmacologicalactivity as such, but may, in certain instances, be administered orallyor parenterally and thereafter metabolised in the body to form compoundsof the invention which are pharmacologically active. Such derivativesmay therefore be described as “prodrugs”. Further, certain compounds ofthe invention may act as prodrugs of other compounds of the invention.All protected derivatives and prodrugs of compounds of the invention areincluded within the scope of the invention. Examples of suitableprotecting groups for the compounds of the present invention aredescribed in Drugs of Today, Volume 19, Number 9, 1983, pp 499-538 andin Topics in Chemistry, Chapter 31, pp 306-316 and in “Design ofProdrugs” by H. Bundgaard, Elsevier, 1985, Chapter 1 (the disclosures inwhich documents are incorporated herein by reference). It will furtherbe appreciated by those skilled in the art, that certain moieties, knownto those skilled in the art as “pro-moieties”, for example as describedby H. Bundgaard in “Design of Prodrugs” (the disclosure in whichdocument is incorporated herein by reference) may be placed onappropriate functionalities when such functionalities are present withincompounds of the invention. Suitable prodrugs for compounds of theinvention include: esters, carbonate esters, hemi-esters, phosphateesters, nitro esters, sulfate esters, sulfoxides, amides, carbamates,azo-compounds, phosphamides, glycosides, ethers, acetals and ketals.

Hereinafter, compounds, their pharmaceutically acceptable salts, theirsolvates and prodrugs, defined in any aspect of the invention (exceptIntermediate compounds in chemical processes) are referred to as“compounds of the invention”.

The compounds of the invention may exist in one or more tautomericforms. All tautomers and mixtures thereof are included in the scope ofthe present invention.

Due to the presence of at least one chiral centre, the compounds of theinvention may exist in the form of optical isomers, e.g.diastereoisomers and mixtures of isomers in all ratios, e.g. racemicmixtures:

The invention includes all such forms, in particular the pure isomericforms. The different isomeric forms may be separated or resolved onefrom the other by conventional methods, or any given isomer may beobtained by conventional synthetic methods or by stereospecific orasymmetric syntheses. It will also be appreciated, in common with mostbiologically active molecules that the level of biological activity mayvary between the individual stereoisomers of a given molecule. It isintended that the scope of the invention includes all individualstereoisomers (diastereoisomers and enantiomers) and all mixturesthereof, including but not limited to racemic mixtures, whichdemonstrate appropriate biological activity with reference to theprocedures described herein.

For the compounds of the present invention, the chiral intermediate,(2S)-5-bromo-2-aminoindane was prepared:

using (1R)-(−)-10-camphorsulphonic acid as resolving agent, as disclosedin Prashad et al, Adv. Synth. Catal. 2001, 343, No. 5, pp 461-472. Theabsolute configuration of (2S)-5-bromo-2-aminoindane(1R)-(−)-10-camphorsulphonic acid salt so obtained was confirmed bysingle crystal X-ray analysis. This compound was used to prepareN-[(2S)-5-bromo-2,3-dihydro-1H-inden-2-yl]-2-propanesulfonamide(Intermediate 6).

In a further embodiment of the present invention, compounds of formula(Ib) or a pharmaceutically acceptable salt, solvate or prodrug thereofare provided which correspond to a stereochemical isomer of compounds offormula (I), enriched in configuration S:

wherein R¹, R², R³, R⁴, R,⁵, R⁶, n, p, and Het are as defined forformula (I).

In another embodiment, the present invention provides a compound offormula (Ic) or a pharmaceutically acceptable salt, solvate or prodrugthereof which correspond to a stereochemical isomer of compounds offormula (Ia), enriched in configuration S:

wherein Het and R¹ are as defined for formula (I).

It is intended in the context of the compounds of the present inventionthat stereochemical isomers enriched in configuration S correspond inone embodiment to at least 90% enantiomeric excess. In anotherembodiment the isomers correspond to at least 95% enantiomeric excess.In another embodiment the isomers correspond to at least 99%enantiomeric excess.

Since the compounds of the invention are intended for use inpharmaceutical compositions it will readily be understood that they areeach preferably provided in substantially pure form, for example atleast 60% pure, more suitably at least 75% pure and preferably at least85%, especially at least 98% pure (% are on a weight for weight basis).Impure preparations of the compounds may be used for preparing the morepure forms used in the pharmaceutical compositions; these less purepreparations of the compounds should contain at least 1%, more suitablyat least 5% and preferably from 10 to 59% of a compound of theinvention.

It will be appreciated that the present invention is intended to includecompounds having any combination of the features hereinbefore mentioned.

Examples of compounds of formula (I) include:

-   N-[5-(2-fluoro-3-pyridinyl)-2,3-dihydro-1H-inden-2-yl]-2-propanesulfonamide-   N-[5-(6-fluoro-3-pyridinyl)-2,3-dihydro-1H-inden-2-yl]-2-propanesulfonamide-   N-[5-(5-pyrimidinyl)-2,3-dihydro-1H-inden-2-yl]-2-propanesulfonamide-   N-[5-(3-thienyl)-2,3-dihydro-1H-inden-2-yl]-2-propanesulfonamide-   N-[5-(3-pyridinyl)-2,3-dihydro-1H-inden-2-yl]-2-propanesulfonamide-   N-[5-(2-thienyl)-2,3-dihydro-1H-inden-2-yl]-2-propanesulfonamide-   N-[5-(4-methyl-3-pyridinyl)-2,3-dihydro-1H-inden-2-yl]-2-propanesulfonamide-   N-[5-(2,6-dimethyl-3-pyridinyl)-2,3-dihydro-1H-inden-2-yl]-2-propanesulfonamide-   N-[5-(6-cyano-3-pyridinyl)-2,3-dihydro-1H-inden-2-yl]-2-propanesulfonamide-   N-[5-(5-acetyl-3-pyridinyl)-2,3-dihydro-1H-inden-2-yl]-2-propanesulfonamide-   N-[5-(5-cyano-3-pyridinyl)-2,3-dihydro-1H-inden-2-yl]-2-propanesulfonamide-   N-[5-(5-fluoro-2-pyridinyl)-2,3-dihydro-1H-inden-2-yl]-2-propanesulfonamide-   N-[5-(4-pyridinyl)-2,3-dihydro-1H-inden-2-yl]-2-propanesulfonamide-   N-[5-(2-pyridinyl)-2,3-dihydro-1H-inden-2-yl]-2-propanesulfonamide-   N-[5-(6-fluoro-2-pyridinyl)-2,3-dihydro-1H-inden-2-yl]-2-propanesulfonamide-   N-[5-(2-methyl-4-pyridinyl)-2,3-dihydro-1H-inden-2-yl]-2-propanesulfonamide-   N-[5-(6-methyl-3-pyridazinyl)-2,3-dihydro-1H-inden-2-yl]-2-propanesulfonamide-   N-[5-(2-pyrimidinyl)-2,3-dihydro-1H-inden-2-yl]-2-propanesulfonamide-   N-[5-(3-fluoro-4-pyridinyl)-2,3-dihydro-1H-inden-2-yl]-2-propanesulfonamide-   N-[5-(6-fluoro-2-methyl-3-pyridinyl)-2,3-dihydro-1H-inden-2-yl]-2-propanesulfonamide-   N-[5-(1H-imidazol-4-yl)-2,3-dihydro-1H-inden-2-yl]-2-propanesulfonamide-   N-[5-(1,3,5-trimethyl-1H-pyrazol-4-yl)-2,3-dihydro-1H-inden-2-yl]-2-propanesulfonamide-   N-[5-(6-methyl-3-pyridinyl)-2,3-dihydro-1H-inden-2-yl]-2-propanesulfonamide-   N-[5-(3-methyl-2-pyridinyl)-2,3-dihydro-1H-inden-2-yl]-2-propanesulfonamide-   N-[5-(5-methyl-2-pyridinyl)-2,3-dihydro-1H-inden-2-yl]-2-propanesulfonamide-   N-[5-(6-chloro-3-pyridinyl)-2,3-dihydro-1H-inden-2-yl]-2-propanesulfonamide-   N-{5-[6-(methyloxy)-3-pyridinyl]-2,3-dihydro-1H-inden-2-yl}-2-propanesulfonamide-   N-[5-(5-chloro-2-pyridinyl)-2,3-dihydro-1H-inden-2-yl]-2-propanesulfonamide-   N-[5-(2-chloro-3-pyridinyl)-2,3-dihydro-1H-inden-2-yl]-2-propanesulfonamide-   N-{(2S)-5-[6-(trifluoromethyl)-3-pyridinyl]-2,3-dihydro-1H-inden-2-yl}-2-propanesulfonamide-   N-[(2S)-5-(5-chloro-2-pyridinyl)-2,3-dihydro-1H-inden-2-yl]-2-propanesulfonamide-   N-{(2S)-5-[6-(trifluoromethyl)-2-pyridinyl]-2,3-dihydro-1H-inden-2-yl}-2-propanesulfonamide-   N-[(2S)-5-(5-methyl-3-pyridinyl)-2,3-dihydro-1H-inden-2-yl]-2-propanesulfonamide-   N-[(2S)-5-(5-fluoro-3-pyridinyl)-2,3-dihydro-1H-inden-2-yl]-2-propanesulfonamide-   N-[(2S)-5-(2-fluoro-6-methyl-3-pyridinyl)-2,3-dihydro-1H-inden-2-yl]-2-propanesulfonamide-   N-[(2S)-5-(2,6-difluoro-3-pyridinyl)-2,3-dihydro-1H-inden-2-yl]-2-propanesulfonamide    and pharmaceutically acceptable salts, solvates and prodrugs    thereof.

Compounds of the invention may be prepared, in known manner in a varietyof ways. In the following reaction schemes and hereafter, unlessotherwise stated R¹ to R⁴, n, p and Het are as defined in formula (I).These processes form further aspects of the invention.

Throughout the specification, general formulae are designated by Romannumerals (I), (II), (III), (IV) etc. Subsets of these general formulaeare defined as (Ia), (Ib), (Ic) etc, . . . (IVa), (IVb), (IVc) etc.

Compounds of general formula (I) may be prepared by reacting compoundsof formula (II) where X is a leaving group such as iodine, with boronicacid or boronate ester derivatives of formula (III) where R is hydrogen,alkyl or two R groups form a ring, according to reaction scheme 1.Typical coupling conditions comprise reacting (II) with (III) in thepresence of a base (such as aqueous cesium carbonate), a palladium (II)catalyst and triphenylphosphine at elevated temperature (such as 80°C.). The boronic acid or boronate ester derivatives of formula (III) maybe readily prepared from the corresponding halide (typically the iodideor bromide). Typical reaction conditions comprise reacting the halidewith a suitable boronate in the presence of a base (such as potassiumacetate) and a palladium (II) catalyst such as(1,1′-bis(diphenylphosphino)ferrocene) palladium (II) chloride, atelevated temperature (such as 80° C.).

Alternatively compounds of formula (I) may be prepared by reactingboronic acid or boronate ester derivatives of formula (IV) where R ishydrogen, alkyl or two R groups form a ring, with compounds of formula(V) (where X is a leaving group typically iodine or bromine) accordingto reaction scheme 2. Typical coupling conditions are the same asdescribed for reaction scheme 1.

Compounds of formula (IIa), i.e. compounds of formula (II) where X isiodine, may be prepared from compounds of formula (VI) according toreaction scheme 3. Typical reaction conditions require treatment of (VI)with strong acid such as sulfuric acid and glacial acetic acid followedby treatment with periodic acid and iodine.

Compounds of formula (VI) may be prepared from compounds of formula(VII) according to reaction scheme 4. Typical reaction conditions areadding sulfonyl chloride (VIII) to an ice-cooled mixture of (VII) and abase (such as 1,8-diazabicyclo[5.4.0]undec-7-ene) in a suitable solvent(such as dichloromethane) and then warming the mixture gradually to roomtemperature.

Compounds of formula (VII) may be prepared from compounds of formula(IX) (see reaction scheme 5) by standard procedures (see SukantaBhattacharyya et al, Synlett 1999, 1781).

Compounds of formula (VII) wherein R², R³, R⁵ and R⁶ are hydrogen and pis 0, is available commercially; for example, 2-aminoindan hydrochloridemay be obtained from Sigma-Aldrich Company Ltd.

Compounds of formula (IX) where at least one of R², R³, R⁵ or R⁶ isother than hydrogen, may be prepared according to reaction scheme 6 fromcompounds of formula (X) by synthetic procedures known in the art,followed by suitable purification, typically chromatography. Forexample, when R², R³, R⁵ or R⁶ is alkyl, typical reaction conditionscomprise stirring an ice-cooled solution of (X) in suitable solvent(such as tetrahydrofuran) followed by consecutive treatment with a basesuch as sodium hydride and an alkylating agent such as an alkyl halide.Alternatively, when R², R³, R⁵ or R⁶ is fluoro, typical reactionconditions comprise reacting (X) with a standard fluorinating agent suchas Accuflour™ in a solvent such as acetonitrile (see Tetrahedron Letters1996, 3591). When R², R³, R⁵ or R⁶ is bromo, typical reaction conditionscomprise stirring an ice-cooled solution of (X) in a suitable solvent(such as tetrahydrofuran) followed by consecutive treatment with a basesuch as sodium hydride and an brominating agent such asN-bromosuccinimide. It will be appreciated by the skilled chemist thatthese bromo intermediates can by further converted into thecorresponding hydroxy/alkoxy compounds by treatment with the sodiumhydroxide/sodium alkoxide respectively in a suitable solvent such astetrahydrofuran.

Alternative preparations of compounds of formula (X) are described inOrganic Letters 2002, Vol. 4, 2465.

Further details for the preparation of compounds of formula (I) arefound in the examples section hereinafter.

Thus, in another aspect, the present invention provides a process forpreparing a compound as defined in claim 1, comprising:

-   (a) reacting a compound of formula (II):

wherein R¹ to R⁶, n and p are as defined for formula (I) and X is aleaving group; with a boronic acid or boronate ester derivative compoundof formula (III):Het-B(OR)₂  (III)wherein Het is as defined for formula (I), and R is hydrogen, alkyl(such as C₁₋₆alkyl) or two R groups form a ring (such as a 5 or 6membered ring);or

-   (b) reacting a boronic acid or boronate ester compound of formula    (IV):

wherein R¹ to R⁶, n and p are as defined for formula (I) and R ishydrogen, alkyl (such as C₁₋₆alkyl) or two R groups form a ring (such asa 5 or 6 membered ring); with a compound of formula (V):Het-X  (V)wherein Het is as defined for formula (I) and X is a leaving group;and optionally thereafter for process (a) or process (b):

-   -   removing any protecting group(s); and/or    -   forming a salt; and/or    -   converting one compound of formula (I) to a different compound        of formula (I).

In process (a), X in formula (II) may be for example halogen such asbromine or iodine. R may be hydrogen, alkyl (such as C₁₋₆alkyl) or two Rgroups may form a ring (such as a 5 or 6 membered ring). For example,the compound of formula (III) may be Het-B(OH)₂.

In process (b), for example, the group —B(OR)₂ in formula (IV) may be4,4,5,5,-tetramethyl-1,3,2-dioxaborolan-2-yl. X in formula (V) may be ahalogen such as Br or I.

The compounds of the invention may be prepared singly or as compoundlibraries comprising at least 2, for example 5 to 1,000 compounds, andmore preferably 10 to 100 compounds. Libraries of compounds of theinvention may be prepared by a combinatorial ‘split and mix’ approach orby multiple parallel synthesis using either solution phase or solidphase chemistry, by procedures known to those skilled in the art. Thusaccording to a further aspect there is provided a compound librarycomprising at least 2 compounds of the invention.

The compounds of the invention may be administered in conventionaldosage forms prepared by combining a compound of the invention withstandard pharmaceutical carriers or diluents according to conventionalprocedures well known in the art. These procedures may involve mixing,granulating and compressing or dissolving the ingredients as appropriateto the desired preparation.

The pharmaceutical compositions of the invention may be formulated foradministration by any route, and include those in a form adapted fororal, topical or parenteral administration to mammals including humans.

The compositions may be formulated for administration by any route. Thecompositions may be in the form of tablets, capsules, powders, granules,lozenges, creams or liquid preparations, such as oral or sterileparenteral solutions or suspensions.

The topical formulations of the present invention may be presented as,for instance, ointments, creams or lotions, eye ointments and eye or eardrops, impregnated dressings and aerosols, and may contain appropriateconventional additives such as preservatives, solvents to assist drugpenetration and emollients in ointments and creams.

The formulations may also contain compatible conventional carriers, suchas cream or ointment bases and ethanol or oleyl alcohol for lotions.Such carriers may be present as from about 1% up to about 98% of theformulation. More usually they will form up to about 80% of theformulation.

Tablets and capsules for oral administration may be in unit dosepresentation form, and may contain conventional excipients such asbinding agents, for example syrup, acacia, gelatin, sorbitol,tragacanth, or polyvinylpyrrolidone; fillers, for example lactose,sugar, maize-starch, calcium phosphate, sorbitol or glycine; tablettinglubricants, for example magnesium stearate, talc, polyethylene glycol orsilica; disintegrants, for example potato starch; or acceptable wettingagents such as sodium lauryl sulphate. The tablets may be coatedaccording to methods well known in normal pharmaceutical practice. Oralliquid preparations may be in the form of, for example, aqueous or oilysuspensions, solutions, emulsions, syrups or elixirs, or may bepresented as a dry product for reconstitution with water or othersuitable vehicle before use. Such liquid preparations may containconventional additives, such as suspending agents, for example sorbitol,methyl cellulose, glucose syrup, gelatin, hydroxyethyl cellulose,carboxymethyl cellulose, aluminium stearate gel or hydrogenated ediblefats, emulsifying agents, for example lecithin, sorbitan monooleate, oracacia; non-aqueous vehicles (which may include edible oils), forexample almond oil, oily esters such as glycerine, propylene glycol, orethyl alcohol; preservatives, for example methyl or propylp-hydroxybenzoate or sorbic acid, and, if desired, conventionalflavouring or colouring agents.

Suppositories will contain conventional suppository bases, e.g.cocoa-butter or other glyceride.

For parenteral administration, fluid unit dosage forms are preparedutilising the compound and a sterile vehicle, water being preferred. Thecompound, depending on the vehicle and concentration used, can be eithersuspended or dissolved in the vehicle. In preparing solutions thecompound can be dissolved in water for injection and filter sterilisedbefore filling into a suitable vial or ampoule and sealing.

Advantageously, agents such as a local anaesthetic, preservative andbuffering agents can be dissolved in the vehicle. To enhance thestability, the composition can be frozen after filling into the vial andthe water removed under vacuum. The dry lyophilised powder is thensealed in the vial and an accompanying vial of water for injection maybe supplied to reconstitute the liquid prior to use. Parenteralsuspensions are prepared in substantially the same manner except thatthe compound is suspended in the vehicle instead of being dissolved andsterilisation cannot be accomplished by filtration. The compound can besterilised by exposure to ethylene oxide before suspending in thesterile vehicle. Advantageously, a surfactant or wetting agent isincluded in the composition to facilitate uniform distribution of thecompound.

The compositions may contain from 0.1% by weight, preferably from 10-60%by weight, of the active material, depending on the method ofadministration. Where the compositions comprise dosage units, each unitwill preferably contain from 50-500 mg of the active ingredient. Thedosage as employed for adult human treatment will preferably range from100 to 3000 mg per day, for instance 1500 mg per day depending on theroute and frequency of administration. Such a dosage corresponds to 1.5to 50 mg/kg per day. Suitably the dosage is from 5 to 20 mg/kg per day.

It will be recognised by one of skill in the art that the optimalquantity and spacing of individual dosages of a compound of theinvention will be determined by the nature and extent of the conditionbeing treated, the form, route and site of administration, and theparticular mammal being treated, and that such optimums can bedetermined by conventional techniques. It will also be appreciated byone of skill in the art that the optimal course of treatment, i.e. thenumber of doses of a compound of the invention given per day for adefined number of days, can be ascertained by those skilled in the artusing conventional course of treatment determination tests.

All publications, including, but not limited to, patents and patentapplications cited in this specification, are herein incorporated byreference as if each individual publication were specifically andindividually indicated to be incorporated by reference herein as thoughfully set forth.

It will be appreciated that the invention includes the following furtheraspects. The features and embodiments described for the first aspectextend these further aspects:

-   i) a pharmaceutical composition comprising a compound of the    invention and a pharmaceutically acceptable carrier or diluent;-   ii) the use of a compound of the invention in the manufacture of a    medicament for treating or preventing a disease or condition caused    by a reduction or imbalance in glutamate receptor function in a    mammal;-   iii) a compound of the invention for use in treating or preventing a    disease or condition caused by a reduction or imbalance in glutamate    receptor function in a mammal;-   iv) a compound of the invention for use as a medicament;-   v) a method of treatment or prevention of a disease or condition    caused by a reduction or imbalance in glutamate receptor function in    a mammal comprising administering an effective amount of a compound    of the invention; and-   vi) a combination of a compound of the invention with an    antipsychotic.

In the case of aspects ii), iii) and v), relevant diseases or conditionsare: psychosis and psychotic disorders (including schizophrenia,schizo-affective disorder, schizophreniform diseases, brief reactivepsychosis, child onset schizophrenia, “schizophrenia-spectrum” disorderssuch as schizoid or schizotypal personality disorders, acute psychosis,alcohol psychosis, drug-induced psychosis, autism, delerium, mania(including acute mania), manic depressive psychosis, hallucination,endogenous psychosis, organic psychosyndrome, paranoid and delusionaldisorders, puerperal psychosis, and psychosis associated withneurodegenerative diseases such as Alzheimer's disease); cognitiveimpairment (e.g. the treatment of impairment of cognitive functionsincluding attention, orientation, memory (i.e. memory disorders,amnesia, amnesic disorders and age-associated memory impairment) andlanguage function, and including cognitive impairment as a result ofstroke, Alzheimer's disease, Aids-related dementia or other dementiastates, as well as other acute or sub-acute conditions that may causecognitive decline such as delirium or depression (pseudodementia states)trauma, aging, stroke, neurodegeneration, drug-induced states,neurotoxic agents), mild cognitive impairment, age related cognitiveimpairment, autism related cognitive impairment, Down's syndrome,cognitive deficit related to psychosis, post-electroconvulsive treatmentrelated cognitive disorders; anxiety disorders (including generalisedanxiety disorder, social anxiety disorder, agitation, tension, social oremotional withdrawal in psychotic patients, panic disorder, andobsessive compulsive disorder); neurodegenerative diseases (such asAlzheimer's disease, amyotrophic lateral sclerosis, motor neuronedisease and other motor disorders such as Parkinson's disease (includingrelief from locomotor deficits and/or motor disability, including slowlyincreasing disability in purposeful movement, tremors, bradykinesia,hyperkinesia (moderate and severe), akinesia, rigidity, disturbance ofbalance and co-ordination, and a disturbance of posture), dementia inParkinson's disease, dementia in Huntington's disease,neuroleptic-induced Parkinsonism and tardive dyskinesias,neurodegeneration following stroke, cardiac arrest, pulmonary bypass,traumatic brain injury, spinal cord injury or the like, anddemyelinating diseases such as multiple sclerosis and amyotrophiclateral sclerosis); depression (which term includes bipolar (manic)depression (including type I and type II), unipolar depression, singleor recurrent major depressive episodes with or without psychoticfeatures, catatonic features, melancholic features, atypical features(e.g. lethargy, over-eating/obesity, hypersomnia) or postpartum onset,seasonal affective disorder and dysthymia, depression-related anxiety,psychotic depression, and depressive disorders resulting from a generalmedical condition including, but not limited to, myocardial infarction,diabetes, miscarriage or abortion); post-traumatic stress syndrome;attention deficit disorder; attention deficit hyperactivity disorder;drug-induced (phencyclidine, ketamine and other dissociativeanaesthetics, amphetamine and other psychostimulants and cocaine)disorders; Huntington's chorea; tardive dyskinesia; dystonia; myoclonus;spasticity; obesity; stroke; sexual dysfunction; and sleep disorders.

Within the context of the present invention, the terms describing theindications used herein are classified in the Diagnostic and StatisticalManual of Mental Disorders, 4th Edition, published by the AmericanPsychiatric Association (DSM-IV) and/or the International Classificationof Diseases, 10th Edition (ICD-10). The various subtypes of thedisorders mentioned herein are contemplated as part of the presentinvention. Numbers in brackets after the listed diseases below refer tothe classification code in DSM-IV.

Within the context of the present invention, the term “psychoticdisorder” includes:

Schizophrenia including the subtypes Paranoid Type (295.30),Disorganised Type (295.10), Catatonic Type (295.20), UndifferentiatedType (295.90) and Residual Type (295.60); Schizophreniform Disorder(295.40); Schizoaffective Disorder (295.70) including the subtypesBipolar Type and Depressive Type; Delusional Disorder (297.1) includingthe subtypes Erotomanic Type, Grandiose Type, Jealous Type, PersecutoryType, Somatic Type, Mixed Type and Unspecified Type; Brief PsychoticDisorder (298.8); Shared Psychotic Disorder (297.3); Psychotic DisorderDue to a General Medical Condition including the subtypes With Delusionsand With Hallucinations; Substance-induced Psychotic Disorder includingthe subtypes With Delusions (293.81) and With Hallucinations (293.82);and Psychotic Disorder Not Otherwise Specified (298.9).

Compounds of formula (I) and pharmaceutically acceptable salts andsolvates thereof may also be of use in the treatment of the followingdisorders:

Depression and mood disorders including Major Depressive Episode, ManicEpisode, Mixed Episode and Hypomanic Episode; Depressive Disordersincluding Major Depressive Disorder, Dysthymic Disorder (300.4),Depressive Disorder Not Otherwise Specified (311); Bipolar Disordersincluding Bipolar I Disorder, Bipolar II Disorder (Recurrent MajorDepressive Episodes with Hypomanic Episodes) (296.89), CyclothymicDisorder (301.13) and Bipolar Disorder Not Otherwise Specified (296.80);Other Mood Disorders including Mood Disorder Due to a General MedicalCondition (293.83) which includes the subtypes With Depressive Features,With Major Depressive-like Episode, With Manic Features and With MixedFeatures), Substance-induced Mood Disorder (including the subtypes WithDepressive Features, With Manic Features and With Mixed Features) andMood Disorder Not Otherwise Specified (296.90):

Anxiety disorders including Panic Attack; Panic Disorder including PanicDisorder without Agoraphobia (300.01) and Panic Disorder withAgoraphobia (300.21); Agoraphobia; Agoraphobia Without History of PanicDisorder (300.22), Specific Phobia (300.29, formerly Simple Phobia)including the subtypes Animal Type, Natural Environment Type,Blood-Injection-Injury Type, Situational Type and Other Type), SocialPhobia (Social Anxiety Disorder, 300.23), Obsessive-Compulsive Disorder(300.3), Posttraumatic Stress Disorder (309.81), Acute Stress Disorder(308.3), Generalized Anxiety Disorder (300.02), Anxiety Disorder Due toa General Medical Condition (293.84), Substance-Induced AnxietyDisorder, Separation Anxiety Disorder (309.21), Adjustment Disorderswith Anxiety (309.24) and Anxiety Disorder Not Otherwise Specified(300.00):

Substance-related disorders including Substance Use Disorders such asSubstance Dependence, Substance Craving and Substance Abuse;Substance-induced Disorders such as Substance Intoxication, SubstanceWithdrawal, Substance-Induced Delirium, Substance-Induced PersistingDementia, Substance-Induced Persisting Amnestic Disorder,Substance-Induced Psychotic Disorder, Substance-Induced Mood Disorder,Substance-Induced Anxiety Disorder, Substance-Induced SexualDysfunction, Substance-Induced Sleep Disorder and HallucinogenPersisting Perception Disorder (Flashbacks); Alcohol-Related Disorderssuch as Alcohol Dependence (303.90), Alcohol Abuse (305.00), AlcoholIntoxication (303.00), Alcohol Withdrawal (291.81), Alcohol IntoxicationDelirium, Alcohol Withdrawal Delirium, Alcohol-Induced PersistingDementia, Alcohol-induced Persisting Amnestic Disorder, Alcohol-InducedPsychotic Disorder, Alcohol-induced Mood Disorder, Alcohol-InducedAnxiety Disorder, Alcohol-Induced Sexual Dysfunction, Alcohol-inducedSleep Disorder and Alcohol-Related Disorder Not Otherwise Specified(291.9); Amphetamine (or Amphetamine-Like)-Related Disorders such asAmphetamine Dependence (304.40), Amphetamine Abuse (305.70), AmphetamineIntoxication (292.89), Amphetamine Withdrawal (292.0), AmphetamineIntoxication Delirium, Amphetamine Induced Psychotic Disorder,Amphetamine-Induced Mood Disorder, Amphetamine-Induced Anxiety Disorder,Amphetamine-Induced Sexual Dysfunction, Amphetamine-induced SleepDisorder and Amphetamine-Related Disorder Not Otherwise Specified(292.9); Caffeine Related Disorders such as Caffeine Intoxication(305.90), Caffeine-induced Anxiety Disorder, Caffeine-induced SleepDisorder and Caffeine-Related Disorder Not Otherwise Specified (292.9);Cannabis-Related Disorders such as Cannabis Dependence (304.30),Cannabis Abuse (305.20), Cannabis Intoxication (292.89), CannabisIntoxication Delirium, Cannabis-Induced Psychotic Disorder,Cannabis-Induced Anxiety Disorder and Cannabis-Related Disorder NotOtherwise Specified (292.9); Cocaine-Related Disorders such as CocaineDependence (304.20), Cocaine Abuse (305.60), Cocaine Intoxication(292.89), Cocaine Withdrawal (292.0), Cocaine Intoxication Delirium,Cocaine-Induced Psychotic Disorder, Cocaine-induced Mood Disorder,Cocaine-induced Anxiety Disorder, Cocaine-Induced Sexual Dysfunction,Cocaine-Induced Sleep Disorder and Cocaine-Related Disorder NotOtherwise Specified (292.9); Hallucinogen-Related Disorders such asHallucinogen Dependence (304.50), Hallucinogen Abuse (305.30),Hallucinogen Intoxication (292.89), Hallucinogen Persisting PerceptionDisorder (Flashbacks) (292.89), Hallucinogen Intoxication Delirium,Hallucinogen-Induced Psychotic Disorder, Hallucinogen-Induced MoodDisorder, Hallucinogen-Induced Anxiety Disorder and Hallucinogen-RelatedDisorder Not Otherwise Specified (292.9); Inhalant-Related Disorderssuch as Inhalant Dependence (304.60), Inhalant Abuse (305.90), InhalantIntoxication (292.89), Inhalant Intoxication Delirium, Inhalant-InducedPersisting Dementia, Inhalant-Induced Psychotic Disorder,Inhalant-Induced Mood Disorder, Inhalant-Induced Anxiety Disorder andInhalant-Related Disorder Not Otherwise Specified (292.9);Nicotine-Related Disorders such as Nicotine Dependence (305.1), NicotineWithdrawal (292.0) and Nicotine-Related Disorder Not Otherwise Specified(292.9); Opioid-Related Disorders such as Opioid Dependence (304.00),Opioid Abuse (305.50), Opioid Intoxication (292.89), Opioid Withdrawal(292.0), Opioid Intoxication Delirium, Opioid-Induced PsychoticDisorder, Opioid-Induced Mood Disorder, Opioid-Induced SexualDysfunction, Opioid-Induced Sleep Disorder and Opioid-Related DisorderNot Otherwise Specified (292.9); Phencyclidine (orPhencyclidine-Like)-Related Disorders such as Phencyclidine Dependence(304.60), Phencyclidine Abuse (305.90), Phencyclidine Intoxication(292.89), Phencyclidine Intoxication Delirium, Phencyclidine-InducedPsychotic Disorder, Phencyclidine-Induced Mood Disorder,Phencyclidine-Induced Anxiety Disorder and Phencyclidine-RelatedDisorder Not Otherwise Specified (292.9); Sedative-, Hypnotic-, orAnxiolytic-Related Disorders such as Sedative, Hypnotic, or AnxiolyticDependence (304.10), Sedative, Hypnotic, or Anxiolytic Abuse (305.40),Sedative, Hypnotic, or Anxiolytic Intoxication (292.89), Sedative,Hypnotic, or Anxiolytic Withdrawal (292.0), Sedative, Hypnotic, orAnxiolytic Intoxication Delirium, Sedative, Hypnotic, or AnxiolyticWithdrawal Delirium, Sedative-, Hypnotic-, or Anxiolytic-PersistingDementia, Sedative-, Hypnotic-, or Anxiolytic-Persisting AmnesticDisorder, Sedative-, Hypnotic-, or Anxiolytic-Induced PsychoticDisorder, Sedative-, Hypnotic-, or Anxiolytic-Induced Mood Disorder,Sedative-, Hypnotic-, or Anxiolytic-Induced Anxiety Disorder Sedative-,Hypnotic-, or Anxiolytic-Induced Sexual Dysfunction, Sedative-,Hypnotic-, or Anxiolytic-Induced Sleep Disorder and Sedative-,Hypnotic-, or Anxiolytic-Related Disorder Not Otherwise Specified(292.9); Polysubstance-Related Disorder such as Polysubstance Dependence(304.80); and Other (or Unknown) Substance-Related Disorders such asAnabolic Steroids, Nitrate Inhalants and Nitrous Oxide:

Sleep disorders including primary sleep disorders such as Dyssomniassuch as Primary Insomnia (307.42), Primary Hypersomnia (307.44),Narcolepsy (347), Breathing-Related Sleep Disorders (780.59), CircadianRhythm Sleep Disorder (307.45) and Dyssomnia Not Otherwise Specified(307.47); primary sleep disorders such as Parasomnias such as NightmareDisorder (307.47), Sleep Terror Disorder (307.46), Sleepwalking Disorder(307.46) and Parasomnia Not Otherwise Specified (307.47); SleepDisorders Related to Another Mental Disorder such as Insomnia Related toAnother Mental Disorder (307.42) and Hypersomnia Related to AnotherMental Disorder (307.44); Sleep Disorder Due to a General MedicalCondition, in particular sleep disturbances associated with suchdiseases as neurological disorders, neuropathic pain, restless legsyndrome, heart and lung diseases; and Substance-Induced Sleep Disorderincluding the subtypes Insomnia Type, Hypersomnia Type, Parasomnia Typeand Mixed Type; sleep apnea and jet-lag syndrome:

Autism Spectrum Disorders including Autistic Disorder (299.00),Asperger's Disorder (299.80), Rett's Disorder (299.80), ChildhoodDisintegrative Disorder (299.10) and Pervasive Disorder Not OtherwiseSpecified (299.80, including Atypical Autism).Attention-Deficit/Hyperactivity Disorder including the subtypesAttention-Deficit/Hyperactivity Disorder Combined Type (314.01),Attention-Deficit/Hyperactivity Disorder Predominantly Inattentive Type(314.00), Attention-Deficit/Hyperactivity Disorder Hyperactive-ImpulseType (314.01) and Attention-Deficit/Hyperactivity Disorder Not OtherwiseSpecified (314.9); Hyperkinetic Disorder; Disruptive Behaviour Disorderssuch as Conduct Disorder including the subtypes childhood-onset type(321.81), Adolescent-Onset Type (312.82) and Unspecified Onset (312.89),Oppositional Defiant Disorder (313.81) and Disruptive Behaviour DisorderNot Otherwise Specified; and Tic Disorders such as Tourette's Disorder(307.23):

Personality Disorders including the subtypes Paranoid PersonalityDisorder (301.0), Schizoid Personality Disorder (301.20), SchizotypalPersonality Disorder (301.22), Antisocial Personality Disorder (301.7),Borderline Personality Disorder (301.83), Histrionic PersonalityDisorder (301.50), Narcissistic Personality Disorder (301.81), AvoidantPersonality Disorder (301.82), Dependent Personality Disorder (301.6),Obsessive-Compulsive Personality Disorder (301.4) and PersonalityDisorder Not Otherwise Specified (301.9):

Enhancement of cognition including the treatment of cognition impairmentin other diseases such as schizophrenia, bipolar disorder, depression,other psychiatric disorders and psychotic conditions associated withcognitive impairment, e.g. Alzheimer's disease: and

Sexual dysfunctions including Sexual Desire Disorders such as HypoactiveSexual Desire Disorder (302.71), and Sexual Aversion Disorder (302.79);sexual arousal disorders such as Female Sexual Arousal Disorder (302.72)and Male Erectile Disorder (302.72); orgasmic disorders such as FemaleOrgasmic Disorder (302.73), Male Orgasmic Disorder (302.74) andPremature Ejaculation (302.75); sexual pain disorder such as Dyspareunia(302.76) and Vaginismus (306.51); Sexual Dysfunction Not OtherwiseSpecified (302.70); paraphilias such as Exhibitionism (302.4), Fetishism(302.81), Frotteurism (302.89), Pedophilia (302.2), Sexual Masochism(302.83), Sexual Sadism (302.84), Transvestic Fetishism (302.3),Voyeurism (302.82) and Paraphilia Not Otherwise Specified (302.9);gender identity disorders such as Gender Identity Disorder in Children(302.6) and Gender Identity Disorder in Adolescents or Adults (302.85);and Sexual Disorder Not Otherwise Specified (302.9).

All of the various forms and sub-forms of the disorders mentioned hereinare contemplated as part of the present invention.

Within the context of the present invention, the term “cognitiveimpairment” includes for example the treatment of impairment ofcognitive functions including attention, orientation, learningdisorders, memory (i.e. memory disorders, amnesia, amnesic disorders,transient global amnesia syndrome and age-associated memory impairment)and language function; cognitive impairment as a result of stroke,Alzheimer's disease, Huntington's disease, Pick disease, Aids-relateddementia or other dementia states such as Multiinfarct dementia,alcoholic dementia, hypotiroidism-related dementia, and dementiaassociated to other degenerative disorders such as cerebellar atrophyand amyotropic lateral sclerosis; other acute or sub-acute conditionsthat may cause cognitive decline such as delirium or depression(pseudodementia states) trauma, head trauma, age related cognitivedecline, stroke, neurodegeneration, drug-induced states, neurotoxicagents, mild cognitive impairment, age related cognitive impairment,autism related cognitive impairment, Down's syndrome, cognitive deficitrelated to psychosis, and post-electroconvulsive treatment relatedcognitive disorders; and dyskinetic disorders such as Parkinson'sdisease, neuroleptic-induced parkinsonism, and tardive dyskinesias.

The compounds of the invention may be used in combination with thefollowing agents to treat or prevent psychotic disorders: i)antipsychotics (such as olanzapine, risperidone, clozapine, ziprazidoneand talnetant); ii) drugs for extrapyramidal side effects, for exampleanticholinergics (such as benztropine, biperiden, procyclidine andtrihexyphenidyl), antihistamines (such as diphenhydramine) anddopaminergics (such as amantadine); iii) antidepressants; iv)anxiolytics; and v) cognitive enhancers for example cholinesteraseinhibitors (such as tacrine, donepezil, rivastigmine and galantamine).

The compounds of the invention may be used in combination withantidepressants to treat or prevent depression and mood disorders.

The compounds of the invention may be used in combination with thefollowing agents to treat or prevent bipolar disease: i) moodstabilisers; ii) antipsychotics; and iii) antidepressants.

The compounds of the invention may be used in combination with thefollowing agents to treat or prevent anxiety disorders: i) anxiolytics;and ii) antidepressants.

The compounds of the invention may be used in combination with thefollowing agents to improve nicotine withdrawal and reduce nicotinecraving: i) nicotine replacement therapy for example a sublingualformulation of nicotine beta-cyclodextrin and nicotine patches; and ii)bupropion.

The compounds of the invention may be used in combination with thefollowing agents to improve alcohol withdrawal and reduce alcoholcraving: i) NMDA receptor antagonists for example acamprosate; ii) GABAreceptor agonists for example tetrabamate; and iii) Opioid receptorantagonists for example naltrexone.

The compounds of the invention may be used in combination with thefollowing agents to improve opiate withdrawal and reduce opiate craving:i) opioid mu receptor agonistopioid kappa receptor antagonist forexample buprenorphine; ii) opioid receptor antagonists for examplenaltrexone; and iii) vasodilatory antihypertensives for examplelofexidine.

The compounds of the invention may be used in combination with thefollowing agents to treat or prevent sleeping disorders: i)benzodiazepines for example temazepam, lormetazepam, estazolam andtriazolam; ii) non-benzodiazepine hypnotics for example zolpidem,zopiclone, zaleplon and indiplon; iii) barbiturates for exampleaprobarbital, butabarbital, pentobarbital, secobarbita andphenobarbital; iv) antidepressants; v) other sedative-hypnotics forexample chloral hydrate and chlormethiazole.

The compounds of the invention may be used in combination with thefollowing agents to treat anorexia: i) appetite stimulants for examplecyproheptidine; ii) antidepressants; iii) antipsychotics; iv) zinc; andv) premenstral agents for example pyridoxine and progesterones.

The compounds of the invention may be used in combination with thefollowing agents to treat or prevent bulimia: i) antidepressants; ii)opioid receptor antagonists; iii) antiemetics for example ondansetron;iv) testosterone receptor antagonists for example flutamide; v) moodstabilisers; vi) zinc; and vii) premenstral agents.

The compounds of the invention may be used in combination with thefollowing agents to treat or prevent autism: i) antipsychotics; ii)antidepressants; iii) anxiolytics; and iv) stimulants for examplemethylphenidate, amphetamine formulations and pemoline.

The compounds of the invention may be used in combination with thefollowing agents to treat or prevent Attention Deficit HyperactivityDisorder: i) stimulants for example methylphenidate, amphetamineformulations and pemoline; and ii) non-stimulants for examplenorepinephrine reuptake inhibitors (such as atomoxetine), alpha 2adrenoceptor agonists (such as clonidine), antidepressants, modafinil,and cholinesterase inhibitors (such as galantamine and donezepil).

The compounds of the invention may be used in combination with thefollowing agents to treat personality disorders: i) antipsychotics; ii)antidepressants; iii) mood stabilisers; and iv) anxiolytics.

The compounds of the invention may be used in combination with thefollowing agents to treat or prevent male sexual dysfunction: i)phosphodiesterase V inhibitors, for example vardenafil and sildenafil;ii) dopamine agonists/dopamine transport inhibitors for exampleapomorphine and buproprion; iii) alpha adrenoceptor antagonists forexample phentolamine; iv) prostaglandin agonists for examplealprostadil; v) testosterone agonists such as testosterone; vi)serotonin transport inhibitors for example serotonin reuptakeinhibitors; v) noradrenaline transport inhibitors for example reboxetineand vii) 5-HT1A agonists, for example flibanserine.

The compounds of the invention may be used in combination with the sameagents specified for male sexual dysfunction to treat or prevent femalesexual dysfunction, and in addition an estrogen agonist such asestradiol.

Antipsychotic drugs include Typical Antipsychotics (for examplechlorpromazine, thioridazine, mesoridazine, fluphenazine, perphenazine,prochlorperazine, trifluoperazine, thiothixine, haloperidol, molindoneand loxapine); and Atypical Antipsychotics (for example clozapine,olanzapine, risperidone, quetiapine, aripirazole, ziprasidone,amisulpride, ziprazidone and talnetant).

Antidepressant drugs include serotonin reuptake inhibitors (such ascitalopram, escitalopram, fluoxetine, paroxetine and sertraline); dualserotonin/noradrenaline reuptake inhibitors (such as venlafaxine,duloxetine and milnacipran); Noradrenaline reuptake inhibitors (such asreboxetine); tricyclic antidepressants (such as amitriptyline,clomipramine, imipramine, maprotiline, nortriptyline and trimipramine);monoamine oxidase inhibitors (such as isocarboxazide, moclobemide,pheneizine and tranylcypromine); and others (such as bupropion,mianserin, mirtazapine, nefazodone and trazodone).

Mood stabiliser drugs include lithium, sodium valproate/valproicacid/divalproex, carbamazepine, lamotrigine, gabapentin, topiramate andtiagabine.

Anxiolytics include benzodiazepines such as alprazolam and lorazepam.

EXAMPLES

The invention is illustrated by the Examples described below.

Starting materials were obtained from commercial suppliers and usedwithout further purification unless otherwise stated. Flashchromatography was carried out using pre-packed Isolute Flash™ orBiotage™ silica-gel columns as the stationary phase and analytical gradesolvents as the eluent. Catch and release purification was carried outusing SCX (strong cation exchanger) cartridges, consisting ofbonded-phase silica with sulfonic acid functional groups. Mass directedpreparative HPLC was carried out using a 19 mm×100 mm or 30 mm×100 mm, 5μm, reversed phase Waters Atlantis column as the stationary phase and agradient from water+0.1% formic acid to acetonitrile+0.1% formic acid asthe eluent. The eluent was monitored by a Waters 996 photodiode arrayand a Micromass ZQ mass spectrometer. For the example compounds, allyields reported are of purified, isolated material. NMR spectra wereobtained at 298K, at the frequency stated using either a Bruker™ DPX400or an Oxford Instruments™ 250 MHz machine and run as a dilute solutionof CDCl₃ unless otherwise stated. All NMR spectra were reference totetramethylsilane (TMS δ_(H) 0, δ_(C)0). All coupling constants arereported in hertz (Hz), and multiplicities are labelled s (singlet), bs,(broad singlet), d (doublet), t (triplet), q (quartet), dd (doublet ofdoublets), dt (doublet of triplets) and m (multiplet).

LC/MS (Liquid Chromatography/Mass Spectrometry) data were obtained usingan Agilent™ 1100HPLC system with a 4.6 mm×50 mm, 3 μm, reversed phaseWaters Atlantis™ column as the stationary phase. A gradient elution from97% water+0.05% formic acid/3% acetonitrile+0.05% formic acid to 97%acetonitrile+0.05% formic acid over 3 minutes plus a further minutecontinuing this mixture at a flow rate of 1.5 mL/min was used as theeluent. Retention time is reported as minutes (with percentage intensityfor DA/ELSD for the relevant peak). Spectroscopic monitoring wasperformed using an Agilent™ 1100 diode array (DA) detector or a Sedex™evaporative light scattering detector (ELSD). Total ion current traceswere obtained for electrospray positive and negative ionisation(ES+/ES−) and atmospheric pressure chemical positive and negativeionisation (AP+/AP−).

Intermediate 1: N-(2,3-dihydro-1H-inden-2-yl)-2-propanesulfonamide

2-Aminoindan hydrochloride (5.16 g, 30 mmol, Sigma-Aldrich Company Ltd)was suspended in dry dichloromethane (100 ml), and cooled with stirringunder argon to 0° C. To the suspension was added1,8-diazabicyclo[5.4.0]undec-7-ene (3 eq., about 14 ml, about 90 mmol)followed by the dropwise addition of isopropylsulfonyl chloride (6.8 ml,60 mmol). The cooling bath was removed and the mixture stirred at roomtemperature for 1 h. The reaction mixture was washed with 1 Mhydrochloric acid (2×50 ml). The organic layer was separated, dried oversodium sulphate and evaporated in vacuo (ie under reduced pressure) togive a yellow oil (11.8 g). The crude product was purified bychromatography on a 50 g Isolute™ Flash silica-gel column eluting from20-50% ethyl acetate in petroleum ether to give the title compound as acolourless solid (6.88 g, 96%).

¹H-NMR (400 MHz, CDCl₃) δ 1.39 (6H, d, J=7 Hz), 2.91 (2H, m), 3.18 (1H,m), 3.31 (2H, m), 4.31 (2H, m), 7.21 (4H, m).

Intermediate 2:N-(5-iodo-2,3-dihydro-1H-inden-2-yl)-2-propanesulfonamide

Intermediate 1 (1.75 g, 7.32 mmol) was dissolved in glacial acetic acid(30 ml) and then treated with concentrated sulfuric acid (0.8 ml)followed by water (2.8 ml) with stirring. This mixture was then treatedwith periodic acid (0.23 eq., 0.38 g, 1.67 mmol) then iodine (0.43 eq.,800 mg, 3.15 mmol), and the whole mix was stirred at 60° C. for 3-4 h.The reaction mixture was allowed to cool and then partitioned betweenethyl acetate and 10% aqueous sodium metabisulfite. The organic layerwas separated and dried over sodium sulphate and evaporated in vacuo togive the title compound as a yellow oil (2.95 g).

Mass spectrum (ES⁻): Found 364 (MH⁻). C₁₂H₁₆INO₂S requires 365; ¹H-NMR(400 MHz, CDCl₃) δ 1.39 (6H, m), 2.90 (2H, m), 3.18 (1H, m), 3.28 (2H,m), 4.28 (1H, m), 4.63 (1H, m), 6.97 (1H, d, J=8 Hz), 7.51 (1H, m), 7.56(1H, m).

Intermediate 3:N-[5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-2,3-dihydro-1H-inden-2-yl]-2-propanesulfonamide

A mixture of (1,1′-bis(diphenylphosphino)ferrocene)palladium(II)chloride complex with dichloromethane (3 mol%, 200 mg, 0.27 mmol),potassium acetate (2.64 g, 26.9 mmol), and bis(pinacolato)diboron (1.1eq., 2.3 g, 9.1 mmol) in dimethylsulfoxide (60 ml) was degassed withargon for 5 mins. A solution of Intermediate 2 (3.0 g, 8.22 mmol) indimethylsulfoxide (20 ml) was added and the resulting mixture stirred at80° C. under argon for 3 h. The reaction mixture was allowed to cool anddiluted with ethyl acetate. This solution was washed with water (3×).The organic layer was separated, dried over sodium sulfate andevaporated under reduced pressure to give a dark oil (3.25 g) which waspurified by chromatography on a 50 g Isolute™ Flash silica-gel column,eluting from 0-50% ethyl acetate in petroleum ether to give the titlecompound as a brown oil (2.60 g, 87%).

Mass spectrum (API−): Found 364 (MH−), C₁₈H₂₈BNO₄S requires 365; ¹H-NMR(250 MHz, CDCl₃): δ 1.34 (12H, s), 1.39 (6H, d, J=7 Hz), 2.90 (2H, m),3.18 (1H, m), 3.32 (2H, m), 4.27 (2H, m), 7.26 (1H, m), 7.65 (2H, m).

Intermediate 4: 5-methyl-3-pyridinyl trifluoromethanesulfonate

In a two-necked round bottomed flask, under nitrogen atmosphere,3-hydroxy-5-methylpyridine (500 mg, 4.58 mmol) was suspended in 10 ml ofdry methylene chloride. Triethylamine was added (2.5 ml, 18.32 mmol, 4eq.) and the resulting solution cooled to 0° C. A solution of triflicanhydride (1.15 ml, 6.87 mmol, 1.5 eq) in 10 ml of dry methylenechloride was then added dropwise. The solution turned purple. After theend of the addition the mixture was stirred keeping the temperature at 0C for 1 h and then allowed to warm to room temperature. The solvent wasremoved under vacuum. The crude oil obtained was taken up in a smallquantity of DCM and loaded on a 25 g Silica cartridge (IST). The columnwas washed with pure cyclohexane and the product collected with acyclohexane/AcOEt 9/1 mixture. The product was obtained in twofractions: a pure one (orange liquid, 260 mg) and a less pure one(orange liquid, 372 mg, additional small spots in TLC and slightaliphatic impurities in the 1H-NMR). Total ˜2.6 mmol, 57% yield.

Mass Spectrum (ES): Found 242 (MH+). C₇H₆F₃NO₃S requires 241. ¹H-NMR(400 MHz, CDCl₃): δ 2.44 (3H, s), 7.46 (1H, s), 8.43 (1H, s), 8.50 (1H,s)

Intermediate 5: (S)-5-bromo-2-aminoindan (camphorsulfonate salt)

The title compound was prepared using a similar method to that describedin Prashad et al, Adv. Synth. Catal. 2001, 343, No. 5, pp 461-472: ie byresolution of the free base form of racemic 5-bromo-2-aminoindan using(1R)-(−)-10-camphorsulphonic acid to obtain (S)-5-bromo-2-aminoindan(1R)-(−)-10-camphorsulfonate salt.

The absolute configuration of (S)-5-bromo-2-aminoindan(1R)-(−)-10-camphorsulfonate salt was confirmed by X-raycrystallography. Furthermore, the enantiomeric purity of(S)-5-bromo-2-aminoindan (1R)-(−)-10-camphorsulfonate salt was checkedby HPLC using the following conditions:

Column: chiralpak AD-H 5 um, 250 × 4.6 mm Mobile phase: A: n-Hexane; B:Ethanol + 0.1% isopropyl amine Gradient: isocratic 8% B Flow rate: 0.8ml/min UV WL range: 200-400 nm Analysis time 17 min

-   Enantiomer 1 was recovered as 0.84% a/a from the racemate. Rt.=11.9    min.-   Enantiomer 2 was recovered as 99.16% a/a from the racemate. Rt.=12.8    min.

Intermediate 6:N-[(2S)-5-bromo-2,3-dihydro-1H-inden-2-yl]-2-propanesulfonamide

In order to obtain the free base form of Intermediate 5, Intermediate 5was treated with NaOH (1M solution in water, at least 1 eq to reachpH=10) in isopropyl acetate as solvent. The free base form ofIntermediate 5 was converted toN-[(2S)-5-bromo-2,3-dihydro-1H-inden-2-yl]-2-propanesulfonamide by asimilar process to the preparation of Intermediate 1, usingdiazabicyclo[5.4.0]undec-7-ene and isopropylsulfonyl chloride

Intermediate 7:N-[(2S)-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-2,3-dihydro-1H-inden-2-yl]-2-propanesulfonamide

Intermediate 6 was converted to Intermediate 7 using a similar method tothe preparation of Intermediate 3 from Intermediate 2, except thatdichloromethane was not used.

Intermediate 8: (R)-5-bromo-2-aminoindan

The title compound was prepared using a similar method to that describedin Prashad et al, Adv. Synth. Catal. 2001, 343, No. 5, pp 461-472: ie byresolution of the free base form of racemic 5-bromo-2-aminoindan using(1S)-(+)-10-camphorsulphonic acid to obtain (R)-5-bromo-2-aminoindan(1S)-(+)-10-camphorsulfonate salt. The enantiomeric purity of(R)-5-bromo-2-aminoindan (1S)-(+)-10-camphorsulfonate salt was checkedby HPLC using the following conditions:

Column: chiralpak AD-H 5 um, 250 × 4.6 mm Mobile phase: A: n-Hexane; B:Ethanol + 0.1% ipa Gradient: isocratic 8% B Flow rate: 0.8 ml/min UVwavelength range: 200-400 nm Analysis time 20 min

-   Enantiomer 1 was recovered as 98.6% a/a from the racemate. Rt.=11.9    min.-   Enantiomer 2 was recovered as 1.4% a/a from the racemate. Rt.=12.9    min.

Intermediate 9:N-(5-bromo-2,3-dihydro-1H-inden-2-yl)-2-propanesulfonamide

The title compound was prepared from 5-bromo-2-aminoindane hydrobromide(Prashad et al, Adv. Synth. Catal. 2001, 343, No. 5, pp 461-472) by asimilar process to the preparation of Intermediate 1.

Mass spectrum (ES⁻): Found 316 (MH⁻). C12H16⁷⁹BrNO2S requires 317;¹H-NMR (400 MHz, CDCl₃) δ 1.39 (6H, m), 2.88 (2H, m), 3.18 (1H, m), 3.28(2H, m), 4.30 (2H, m), 7.08 (1H, d, J=8 Hz), 7.31 (1H, m), 7.35 (1H, m).

Example 1N-[5-(2-fluoro-3-pyridinyl)-2,3-dihydro-1H-inden-2-yl]-2-propanesulfonamide

A mixture of Intermediate 2 (65 mg, 0.18 mmol) and cesium carbonate (1.5eq, 88 mg, 0.27 mmol) in a 3:1 mixture of 1,4-dioxan:water (4 ml) wasdegassed with argon for 5 minutes. Then the mixture was added to(2-fluoro-3-pyridinyl)boronic acid (1.1 eq, 28 mg, 0.20 mmol, AsymchemInternational Inc.). Palladium acetate (2 mg, 0.01 mmol—alternatively,solid supported palladium may be used), and triphenylphosphine (9 mg,0.03 mmol) were then added and the whole mixture stirred at reflux for16 h. The reaction mixture was allowed to cool and partitioned betweenethyl acetate (10 ml) and water (10 ml). The organic layer wasseparated, dried and evaporated. The resulting product was purifiedusing mass directed preparative HPLC to give the title compound (22 mg,37%).

Mass spectrum (API+): Found 335 (MH+), C₁₇H₁₉FN₂O₂S requires 334; ¹H-NMR(400 MHz, CDCl₃): δ 1.41 (6H, d, J=7 Hz), 2.98 (2H, m), 3.21 (1H, m),3.38 (2H m,), 4.35 (2H, m), 7.38 (3H, m), 7.66 (1H, m), 7.84 (1H, m),8.19 (1H, m).

Example 2N-[5-(6-fluoro-3-pyridinyl)-2,3-dihydro-1H-inden-2-yl]-2-propanesulfonamide

The title compound was prepared by a similar process to the preparationof Example 1, starting from Intermediate 2 with(6-fluoro-3-pyridinyl)boronic acid, except that, instead of stirring themixture at conventional reflux for 16 h, the reaction mixture wasstirred in a microwave reactor at 160° C. for 20 minutes.

Mass spectrum (API+): Found 335 (MH+), C17H19FN₂O₂S requires 334; 1H-NMR(250 MHz, CDCl3): δ 1.41 (6H, d, J=7 Hz), 2.98 (2H, m), 3.21 (1H, m),3.38 (2H, m), 4.40 (2H, m), 7.00 (1H, m), 7.32 (3H, m), 7.93 (1H, m),8.37 (1H, m).

The title compound was also prepared starting from Intermediate 9, by asimilar process to the preparation of Example 1, using(6-fluoro-3-pyridinyl)boronic acid.

Mass spectrum (ES+): Found 335 (MH+), C17H19FN₂O₂S requires 334; 1H-NMR(400 MHz, CDCl3): δ 1.41 (6H, d, J=7 Hz), 2.98 (2H, m), 3.21 (1H, m),3.38 (2H m), 4.35 (1H, m), 4.45 (1H, m), 7.00 (1H, dd, J=8 & 2 Hz), 7.34(3H, m), 7.93 (1H, m), 8.37 (1H, m).

The racemic compound was separated to give the two enantiomers by HPLCusing the following conditions:

Column: Chiralpak AS-H 5 um, 250 × 4.6 mm, Mobile phase: A: n-Hexane; B:Ethanol Gradient: isocratic 30% B Flow rate: 0.8 ml/min UV WL range:200-400 nm Analysis time 20 min

-   Enantiomer 1 was recovered as 51.4% a/a from the racemate. Rt.=16.2    min.-   Enantiomer 2 was recovered as 48.6% a/a from the racemate. Rt.=17.7    min.

The enantiomers of Example 2 can be prepared using enantiomerically pureintermediates.

Example 2aN-[(2S)-5-(6-fluoro-3-pyridinyl)-2,3-dihydro-1H-inden-2-yl]-2-propanesulfonamide

-   -   Intermediate 6 was reacted with (6-fluoro-3-pyridinyl)boronic        acid in a similar process used for the preparation of Example 1,        except that, instead of stirring the mixture at conventional        reflux for 16 h, the reaction mixture was stirred in a microwave        reactor at 160° C. for 20 minutes; and instead of palladium        acetate and triphenylphosphine, polymer bound        tetrakis(triphenylphosphine)-palladium was used; to obtain        N-[(2S)-5-(6-fluoro-3-pyridinyl)-2,3-dihydro-1H-inden-2-yl]-2-propanesulfonamide.        The enantiomeric purity of the        N-[(2S)-5-(6-fluoro-3-pyridinyl)-2,3-dihydro-1H-inden-2-yl]-2-propanesulfonamide        obtained was checked by HPLC using the same conditions as for        the separation of the racemic compound above. Enantiomer 1 was        recovered as 2.08% a/a from the racemate. Rt.=16.3 min.        Enantiomer 2 was recovered as 97.92% a/a from the racemate.        Rt.=17.7 min. Enantiomer 2 was confirmed to be        N-[(2S)-5-(6-fluoro-3-pyridinyl)-2,3-dihydro-1H-inden-2-yl]-2-propanesulfonamide        by X ray crystrallography.

Example 2bN-[(2R)-5-(6-fluoro-3-pyridinyl)-2,3-dihydro-1H-inden-2-yl]-2-propanesulfonamide

-   -   The title compound was prepared using a similar process for        Example 2a, by first using Intermediate 8 in order to prepare        the corresponding propanesulfonamide. The enantiomeric purity of        the        N-[(2R)-5-(6-fluoro-3-pyridinyl)-2,3-dihydro-1H-inden-2-yl]-2-propanesulfonamide        obtained was checked by HPLC using the same conditions as for        the separation of racemic Example 2 above, except that the        analysis time was 22 minutes. Enantiomer 1 was recovered as        99.04% a/a from the racemate. Rt.=16.62 min. Enantiomer 2 was        recovered as 0.96% a/a from the racemate. Rt.=18.29 min.

The following compounds of formula (A) (see Table 1), i.e. compounds ofgeneral formula (I) where R¹ is isopropyl, n is 1, R² and R³ arehydrogen and p is 0, were prepared by methods similar to the preparationof Example 1, starting from Intermediate 2 together with the appropriateboronic acid. The boronic acids are all commercially available from oneor more of the following suppliers: Asymchem International Inc.,Frontier Scientific Inc. and Sigma Aldrich Company Ltd.

TABLE 1 (A)

Eg Het Physical data 3 5- mass spectrum (API+): Found 317 (MH+),pyrimidinyl C₁₆H₁₉N₃O₂S requires 316; ¹H-NMR (400 MHz, CDCl₃): 1.41 (6H,d, J = 7 Hz), 3.02 (2H, m), 3.21 (1H, m), 3.43 (2H, m), 4.37 (1H, m),4.69 (1H, m), 7.37 (3H, m), 8.87 (2H, m), 9.18 (1H, m). 4 3-thienyl massspectrum (API−): Found 319 (MH−), C₁₆H₁₉NO₂S₂ requires 320; ¹H-NMR (400MHz, CDCl₃): 1.39 (6H, m), 2.93 (2H, m), 3.19 (1H, m), 3.34 (2H, m),4.32 (1H, m), 4.41 (1H, m), 7.39 (6H, m). 5 3-pyridyl mass spectrum(API+): Found 317 (MH+), C₁₇H₂₀N₂O₂S requires 316; ¹H-NMR (400 MHz,CDCl₃): 1.40 (6H, d, J = 7 Hz), 3.00 (2H, m), 3.21 (1H, m), 3.37 (2H,m), 4.34 (1H, m), 5.04 (1H, m), 3.32 (1H, m), 7.41 (3H, m), 7.91 (1H,m), 8.57 (1H, m), 8.75 (1H, m). 6 2-thienyl mass spectrum (API−): Found319 (MH−), C₁₆H₁₉NO₂S₂ requires 320; ¹H-NMR (400 MHz, CDCl₃): 1.38 (6H,d, J = 7 Hz), 2.92 (2H, m), 3.16 (1H, m), 3.27 (2H, m), 4.29 (1H, m),4.54 (1H, m), 7.06 (1H, m), 7.20 (1H, m), 7.25 (2H, m), 7.43 (2H, m).

Example 7N-[5-(4-methyl-3-pyridinyl)-2,3-dihydro-1H-inden-2-yl]-2-propanesulfonamide

A mixture of Intermediate 3 (80 mg, 0.22 mmol), 3-bromo-4-methylpyridine(1 eq, 38 mg, 0.22 mmol) and cesium carbonate (1.5 eq, 108 mg, 0.33mmol) in a 3:1 mixture of 1,4-dioxan:water (4 ml) was degassed withargon for 5 minutes. Palladium acetate (2 mg, 0.01 mmol), followed bytriphenylphosphine (12 mg, 0.04 mmol) were then added and the wholemixture stirred at 160° C. for 20 mins in a microwave reactor. Thereaction mixture was allowed to cool and partitioned between ethylacetate and water. The organic layer was separated and evaporated underreduced pressure. The resulting product was purified on a 5 g Isolute™Flash silica-gel column, eluting from 0-40% ethyl acetate in petroleumether to give the title compound as a yellow oil (38 mg, 52%).

Mass spectrum (API+): Found 331 (MH+), C₁₈H₂₂N₂O₂S requires 330; ¹H-NMR(400 MHz, CDCl₃): δ 1.41 (6H, d, J=7 Hz), 2.73 (3H, s), 2.99 (2H, m),3.21 (1H, m), 3.38 (2H, m), 4.36 (1H, m), 4.74 (1H, m), 7.12 (1H, dd,J=8 Hz and 1 Hz), 7.17 (2H, m), 7.29 (1H, d, J=8 Hz), 8.30 (1H, s), 8.43(1H, d, J=5 Hz).

The following compounds of formula (A) (see Table 2), i.e. compounds ofgeneral formula (I) where R¹ is isopropyl, n is 1, R² and R³ arehydrogen and p is 0, were prepared by methods similar to the preparationof Example 7, starting from Intermediate 3 together with the appropriatepyridyl, pyrimidinyl, imidazolyl or 5 pyridazinyl halide. Such halidesare all commercially available from one or more of the followingsuppliers: Apollo Scientific Ltd. and Lancaster Synthesis Ltd.

TABLE 2 (A)

Eg Het Physical data 8

mass spectrum (API+): Found 345 (MH+), C₁₉H₂₄N₂O₂S requires 344; ¹H-NMR(400 MHz, CDCl₃): 1.41 (6H, d, J = 7 Hz), 2.47 (3H, s), 2.57 (3H, s),2.96 (2H, m), 3.21 (1H, m), 3.37 (2H, m), 4.37 (2H, m), 7.04 (1H, d, J =8 Hz), 7.13 (2H, m), 7.26 (1H, m), 7.38 (1H, d, J = 8 Hz). 9

mass spectrum (API+): Found 342 (MH+), C₁₈H₁₉N₃O₂S requires 341; ¹H-NMR(400 MHz, CDCl₃): 1.41 (6H, d, J = 7 Hz), 3.00 (2H, m), 3.21 (1H, m),3.38 (2H, m), 4.37 (2H, m), 7.40 (3H, m), 7.76 (1H, m), 7.97 (1H, m),8.91 (1H, m). 10

mass spectrum (API+): Found 359 (MH+), C₁₉H₂₂N₂O₃S requires 358; ¹H-NMR(400 MHz, CDCl₃): 1.41 (6H, d, J = 7 Hz), 2.69 (3H, s), 3.00 (2H, m),3.21 (1H, m), 3.40 (2H, m), 4.36 (1H, m), 4.56 (1H, m), 7.35 (1H, m),7.45 (3H, m), 7.67 (1H, m), 8.37 (1H, m). 11

mass spectrum (ES+): Found 342 (MH+), C₁₈H₁₉N₃O₂S requires 341; ¹H-NMR(400 MHz, CDCl₃): 1.41 (6H, d, J = 7 Hz), 3.00 (2H, m), 3.21 (1H, m),3.40 (2H, m), 4.35 (1H, m), 4.49 (1H, m), 7.38 (2H, m), 7.42 (1H, m),8.09 (1H, m), 8.83 (1H, m), 8.97 (1H, m). 12

mass spectrum (APCI): Found 335 (MH+), C₁₇H₁₉FN₂O₂S requires 334; ¹H-NMR(400 MHz, CDCl₃): 1.40 (6H, m), 2.96 (2H, m), 3.20 (1H, m), 3.38 (2H,m), 4.34 (2H, m), 7.31 (1H, m), 7.47 (1H, m), 7.71 (2H, m), 7.81 (1H,m), 8.52 (1H, m) Using similar methods, Example 12 was also prepared asa single enantiomer starting with Intermediate 6 which was used toprepare Intermediate 7; except that, instead of palladium acetate andtriphenylphosphine, polymer bound tetrakis(triphenylphosphine)-palladiumwas used. Intermediate 7 was then reacted with the appropriate pyridylhalide to give an enantiomeric compound which is believed to beN-[(2S)-5-(5-fluoro-2- pyridinyl)-2,3-dihydro-1H-inden-2-yl]-2-propanesulfonamide due to the use ofIntermediate 6. 13

mass spectrum (APCI): Found 317 (MH+), C₁₇H₂₀N₂O₂S requires 316; ¹H-NMR(400 MHz, CDCl₃): 1.41 (6H, m), 2.99 (2H, m), 3.21 (1H, m), 3.38 (2H,m), 4.35 (1H, m), 4.58 (1H, m), 7.32 (1H, m), 7.46 (3H, m), 7.67 (1H,m), 8.64 (2H, m). 14

mass spectrum (APCI): Found 317 (MH+), C₁₇H₂₀N₂O₂S requires 316; ¹H-NMR(400 MHz, CDCl₃): 1.40 (6H, m), 2.95 (2H, m), 3.19 (1H, m), 3.36 (2H,m), 4.34 (1H, m), 4.47 (1H, m), 7.23 (1H, m), 7.30 (1H, d, J = 8 Hz),7.69 (1H, m), 7.76 (2H, m), 7.86 (1H, s), 8.68 (1H, m). 15

mass spectrum (APCI): Found 335 (MH+), C₁₇H₁₉FN₂O₂S requires 334; ¹H-NMR(400 MHz, CDCl₃): 1.40 (6H, m), 2.97 (2H, m), 3.20 (1H, m), 3.37 (2H,m), 4.35 (2H, m), 6.85 (1H, dd, J = 8 Hz and 3 Hz), 7.30 (1H, m), 7.59(1H, dd, J = 7 Hz and 2 Hz), 7.84 (3H, m). 16

mass spectrum (APCI): Found 331 (MH+), C₁₈H₂₂N₂O₂S requires 330; ¹H-NMR(400 MHz, CDCl₃): 1.41 (6H, m), 2.67 (3H. s), 2.99 (2H, m), 3.21 (1H,m), 3.39 (2H, m), 4.36 (1H, m), 4.45 (1H, m), 7.34 (1H, d, J = 8 Hz),7.41-7.49 (3H, m), 8.23 (1H, s), 8.59 (1H, m). 17

mass spectrum (APCI): Found 332 (MH+), C₁₇H₂₁N₃O₂S requires 331; ¹H-NMR(250 MHz, CDCl₃): 1.41 (6H, m), 2.76 (3H, s), 3.00 (2H, m), 3.21 (1H,m), 3.39 (2H, m), 4.37 (1H, m), 4.49 (1H, m), 7.36 (2H, m), 7.49 (1H,m), 7.83 (1H, m), 7.94 (1H, s). 18

mass spectrum (APCI): Found 318 (MH+), C₁₆H₁₉N₃O₂S requires 317; ¹H-NMR(400 MHz, CDCl₃): 1.40 (6H, m), 2.98 (2H, m), 3.20 (1H, m), 3.39 (2H,m), 4.35 (2H, m), 7.18 (1H, m), 7.33 (1H, m), 8.28 (2H, m), 8.79 (2H, d,J = 5 Hz). 19

mass spectrum (APCI): Found 333 (MH−), C₁₇H₁₉FN₂O₂S requires 334; ¹H-NMR(400 MHz, CDCl₃): 1.41 (6H, m), 2.97 (2H, m), 3.21 (1H, m), 3.38 (2H,m), 4.34 (2H, m), 7.36 (2H, m), 7.47 (2H, m), 8.45 (1H, m), 8.53 (1H,m). 20

mass spectrum (ES): Found 349 (ES+), C₁₈H₂₁FN₂O₂S requires 348; ¹H-NMR(250 MHz, CDCl₃): 1.41 (6H, m), 2.43 (3H, s), 2.97 (2H, m), 3.21 (1H,m), 3.38 (2H, m), 4.38 (2H, m), 6.80 (1H, m), 7.11 (2H, m), 7.28 (1H,m), 7.58 (1H, m). 21

mass spectrum (ES): Found 306 (ES+), C₁₅H₁₉N₃O₂S requires 305; ¹H-NMR(400 MHz, CDCl₃): 1.40 (6H, m), 2.93 (2H, m), 3.20 (1H, m), 3.34 (2H,m), 4.33 (2H, M), 7.23 (1H, m), 7.30 (1H, m), 7.54 (1H, m), 7.60 (1H,s), 7.74 (1H, s). 22

mass spectrum (ES): Found 348 (ES+), C₁₈H₂₅N₃O₂S requires 347; ¹H-NMR(400 MHz, CDCl₃): 1.41 (6H, d, J = 7 Hz), 2.23 (6H, s), 2.94 (2H, m),3.20 (1H, m), 3.35 (2H, m), 3.78 (3H, s), 4.33 (2H, m), 7.06 (2H, m),7.25 (1H, m). 23

mass spectrum (ES): Found 331 (ES+), C₁₈H₂₂N₂O₂S requires 330; ¹H-NMR(400 MHz, CDCl₃): 1.41 (6H, m), 2.60 (3H, s), 2.97 (2H, m), 3.20 (1H,m), 3.38 (2H, m), 4.35 (2H, m), 7.21 (1H, d, J = 8 Hz), 7.30 (1H, m),7.38 (2H, m), 7.73 (1H, dd, J = 8 Hz & 2 Hz), 8.68 (1H, d, J = 2 Hz).Using similar methods, Example 23 was alsoprepared as a singleenantiomer starting with Intermediate 6 which was used to prepareIntermediate 7, except that, instead of palladium acetate andtriphenylphosphine, polymer bound tetrakis(triphenylphosphine)-palladiumwas used. Intermediate 7 was then reacted with the appropriate pyridylhalide to give an enantiomeric compound which is believed to beN-[(2S)-5-(6-methyl- 3-pyridinyl)-2,3-dihydro-1H-inden-2-yl]-2-propanesulfonamide due to the use of Intermediate 6. 24

mass spectrum (ES): Found 331 (ES+), C₁₈H₂₂N₂O₂S requires 330; ¹H-NMR(400 MHz, CDCl₃): 1.41 (6H, m), 2.34 (3H, s), 2.89 (2H, m), 3.19 (1H,m), 3.33 (2H, m), 4.32 (1H, m), 4.67 (1H, m), 7.18 (1H, m), 7.28 (2H,m), 7.37 (1H, s), 7.58 (1H, m), 8.53 (1H, m). 25

mass spectrum (ES): Found 331 (ES+), C₁₈H₂₂N₂O₂S requires 330; ¹H-NMR(400 MHz, CDCl₃): 1.39 (6H, m), 2.37 (3H, s), 2.95 (2H, m), 3.24 (1H,m), 3.36 (2H, m), 4.33 (1H, m), 4.41 (1H, m), 7.29 (1H, d, J = 8 Hz),7.57 (2H, m), 7.75 (1H, dd, J = 8 Hz & 2 Hz), 7.83 (1H, s), 8.50 (1H,m). 26

mass spectrum (ES): Found 351 (ES+), C₁₇H₁₉ ³⁵CIN₂O₂S requires 350;¹H-NMR (400 MHz, CDCl₃): 1.40 (6H, d, J = 7 Hz), 2.98 (2H, m), 3.21 (1H,m), 3.38 (2H, m), 4.36 (2H, m), 7.36 (4H, m), 7.80 (1H, dd, J = 8 Hz & 2Hz), 8.56 (1H, m) 27

mass spectrum (ES): Found 347 (ES+), C₁₈H₂₂N₂O₃S requires 346; ¹H-NMR(400 MHz, CDCl₃): 1.41 (6H, m), 2.96 (2H, m), 3.20 (1H, m), 3.37 (2H,m), 3.98 (3H, s), 4.31 (2H, m), 6.81 (1H, m), 7.29 (1H, m), 7.35 (2H,m), 7.75 (1H, dd, J = 8 Hz & 2 Hz), 8.34 (1H, m). 28

mass spectrum (ES): Found 351 (ES+), C₁₇H₁₉ ³⁵CIN₂O₂S requires 350;¹H-NMR (400 MHz, CDCl₃): 1.40 (6H, m), 2.96 (2H, m), 3.21 (1H, m), 3.38(2H, m), 4.33 (2H, m), 7.31 (1H, d, J = 8 Hz), 7.64 (1H, m), 7.74 (2H,m), 7.84 (1H, m), 8.62 (1H, m). 29

mass spectrum (ES): Found 351 (ES+), C₁₇H₁₉ ³⁵CIN₂O₂S requires 350;¹H-NMR (400 MHz, CDCl₃): 1.41 (6H, m), 2.99 (2H, m), 3.31 (1H, m), 3.38(2H, m), 4.35 (1H, m), 4.47 (1H, m), 7.29 (4H, m), 7.65 (1H, dd, J = 7Hz & 2 Hz), 8.39 (1H, m).

Example 30N-{(2S)-5-[6-(trifluoromethyl)-3-pyridinyl]-2,3-dihydro-1H-inden-2-yl}-2-propanesulfonamide

To a solution ofN-[(2S)-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-2,3-dihydro-1H-inden-2-yl]-2-propanesulfonamide(190 mg, 0.52 mmol) in dry 1,4 dioxane (5 ml), polymer supportedPd(PPh₃)₄ (10 mg, 0.5 mmol/g, 0.005 mmol) was added along with5-bromo-2-(trifluoromethyl)pyridine (176 mg, 0.78 mmol) and 500 μl of a2M Na₂CO₃ solution in water. The resulting mixture was heated at 90°degrees for 3 hours. Then after cooling the resin was removed byfiltration and then the solvent was removed under reduced pressure. Theresidue was taken up with DCM, washed with water and loaded on a 25M+silica cartridge eluating with a cyclohexane/AcOEt 75/25 mixture. 150 mgof title compound were recovered as whitish solid (75%). Due to the useof chiral Intermediate 7, the final compound is believed to beN-{(2S)-5-[6-(trifluoromethyl)-3-pyridinyl]-2,3-dihydro-1H-inden-2-yl}-2-propanesulfonamide.

Mass spectrum (ES): Found 385 (MH+), C₁₈H₁₉F₃N₂O₂S requires 384; ¹H-NMR(500MHz, DMSO-d6): 1.26 (6H, d, J=7 Hz), 2.92 (2H, m), 3.23 (3H, m),4.14 (1H, m), 7.37 (1H, d, J=8 Hz), 7.48 (1H, d, J=8 Hz), 7.59 (1H, d,J=9 Hz), 7.65 (1H, m), 7.95 (1H, d, J=9 Hz), 8.31 (1H, m), 9.05 (1H, m)

Example 31N-[(2S)-5-(5-chloro-2-pyridinyl)-2,3-dihydro-1H-inden-2-yl]-2-propanesulfonamide

To a solution ofN-[(2S)-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-2,3-dihydro-1H-inden-2-yl]-2-propanesulfonamide(1 g, 2.74 mmol) in dry 1,4 dioxane (15 ml), polymer supported Pd(PPh₃)₄(54 mg, 0.5 mmol/g, 0.027 mmol) was added along with2-bromo-5-chloropyridine (1.05 g, 5.48 mmol) and 3.5 ml of a 2M Na₂CO₃solution in water and the resulting mixture was heated at 90° degreesfor 3 hours. Then after cooling the resin was removed by filtration andthen the solvent was removed under reduced pressure. The residue wastaken up with AcOEt and water. The aqueous phase was separated andacidified with 3N HCl and extracted with AcOEt. Then pH was reverted tobasic by addition of NaHCO₃ and another extraction with AcOEt wasperformed. All the organic extracts were collected, dried on Na₂SO₄,filtered and evaporated. The crude was finally purified on a 40M+ silicacartridge eluting with a cyclohexane/AcOEt 80/20 mixture. 682 mg oftitle compound were recovered as whitish solid (71%). Due to the use ofchiral Intermediate 7, the final compound is believed to beN-[(2S)-5-(5-chloro-2-pyridinyl)-2,3-dihydro-1H-inden-2-yl]-2-propanesulfonamide.

Mass spectrum (ES): Found 351 (MH+), C₁₇H₁₉ ³⁵ClN₂O₂S requires 350;¹H-NMR (500MHz, DMSO-d6): 1.25 (6H, d, J=7 Hz), 2.90 (2H, m), 3.24 (3H,m), 4.14 (1H, m), 7.31 (1H, d, J=8 Hz), 7.46 (1H, d, J=8 Hz), 7.86 (1H,m), 7.90 (1H, m), 7.96 (2H, m), 8.66 (1H, m)

Example 32N-{(2S)-5-[6-(trifluoromethyl)-2-pyridinyl]-2,3-dihydro-1H-inden-2-yl}-2-propanesulfonamide

To a solution ofN-[(2S)-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-2,3-dihydro-1H-inden-2-yl]-2-propanesulfonamide(190 mg, 0.52 mmol) in dry 1,4 dioxane (5 ml), polymer supportedPd(PPh₃)₄ (10 mg, 0.5 mmol/g, 0.005 mmol) was added along with2-Bromo-6-trifluoromethylpyridine (174 mg, 0.78 mmol) and 500 μl of a 2MNa₂CO₃ solution in water and the resulting mixture was heated at 90°degrees for 3 hours. Then after cooling the resin was removed byfiltration and then the solvent was removed under reduced pressure. Theresidue was taken up with DCM, washed with water and loaded on a 25M+silica cartridge eluating with a cyclohexane/AcOEt 75/25 mixture. 95 mgof title compound were recovered as whitish solid (47%). Due to the useof chiral Intermediate 7, the final compound is believed to beN-{(2S)-5-[6-(trifluoromethyl)-2-pyridinyl]-2,3-dihydro-1H-inden-2-yl}-2-propanesulfonamide.

Mass spectrum (ES): Found 385 (MH+), C₁₈H₁₉F₃N₂O₂S requires 384; ¹H-NMR(500 MHz, DMSO-d6): 1.26 (6H, d, J=7 Hz), 2.92 (2H, m), 3.23 (3H, m),4.14 (1H, m), 7.36 (1H, d, J=8 Hz), 7.47 (1H, m), 7.81 (1H, d, J=8 Hz),7.92 (1H, d, J=8 Hz), 7.95 (1H, m), 8.14 (1H, t, J=7 Hz), 8.24 (1H, d,J=8 Hz)

Example 33N-[(2S)-5-(5-methyl-3-pyridinyl)-2,3-dihydro-1H-inden-2-yl]-2-propanesulfonamide

To a solution ofN-[(2S)-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-2,3-dihydro-1H-inden-2-yl]-2-propanesulfonamide(250 mg, 0.68 mmol) in dry 1,4 dioxane (5 ml), polymer supportedPd(PPh₃)₄ (70 mg, 0.11 mmol/g, 0.0068 mmol) was added along with5-methyl-3-pyridinyl trifluoromethanesulfonate (241 mg, 1.026 mmol) and680 μl of a 2M Na₂CO₃ solution in water and the resulting mixture washeated at 90° degrees for 3 hours. Then after cooling the resin wasremoved by filtration and then the solvent was removed under reducedpressure. The residue was taken up with DCM, washed with water andloaded on a 25M+ silica cartridge eluating with a cyclohexane/AcOEt75/25 mixture. 95 mg of title compound were recovered as whitish solid(42%). Due to the use of chiral Intermediate 7, the final compound isbelieved to beN-[(2S)-5-(5-methyl-3-pyridinyl)-2,3-dihydro-1H-inden-2-yl]-2-propanesulfonamide.

Mass spectrum (ES): Found 331 (MH+), C₁₈H₂₂N₂O₂S requires 330; ¹H-NMR(400 MHz, CDCl₃): 1.43 (6H, d, J=7 Hz), 2.43 (3H, m), 3.01 (2H, m), 3.23(1H, m), 3.40 (2H, m), 4.38 (1H, m), 4.65 (1H, m), 7.34 (1H, d, J=8 Hz),7.40 (1H, d, J=8 Hz), 7.43 (1H, m), 7.71 (1H, m), 8.44 (1H, m), 8.56(1H, m)

Example 34N-[(2S)-5-(5-methyl-3-pyridinyl)-2,3-dihydro-1H-inden-2-yl]-2-propanesulfonamide

To a solution ofN-[(2S)-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-2,3-dihydro-1H-inden-2-yl]-2-propanesulfonamide(700 mg, 1.92 mmol) in dry 1,4 dioxane (15 ml), polymer supportedPd(PPh₃)₄ (38 mg, 0.5 mmol/g, 0.019 mmol) was added along with3-bromo-5-fluoropyridine (675 mg, 3.83 mmol) and 2.7 ml of a 2M Na₂CO₃solution in water and the resulting mixture was heated at 90° degreesfor 3 hours. Then after cooling the resin was removed by filtration andthen the solvent was removed under reduced pressure. The residue wastaken up with AcOEt and water. The aqueous phase was separated andacidified with 3N HCl and extracted with AcOEt. Then pH was reverted tobasic by addition of NaHCO₃ and another extraction with AcOEt wasperformed. All the organic extracts were collected, dried on Na₂SO₄,filtered and evaporated. The crude was finally purified on a 40M+ silicacartridge eluting with a cyclohexane/AcOEt 80/20 mixture. 270 mg oftitle compound were recovered as whitish solid along with 240 mg ofslightly less pure fractions (overall yield 79%). Due to the use ofchiral Intermediate 7, the final compound is believed to beN-[(2S)-5-(5-methyl-3-pyridinyl)-2,3-dihydro-1H-inden-2-yl]-2-propanesulfonamide.

Mass spectrum (ES): Found 335 (MH+), C₁₇H₁₉FN₂O₂S requires 334; ¹H-NMR(400 MHz, CDCl₃): 1.43 (6H, d, J=7 Hz), 3.01 (2H, m), 3.23 (1H, m), 3.42(2H, m) 4.30 (1H, d, J=8 Hz), 4.39 (1H, m), 7.37 (1H, d, J=8 Hz), 7.42(1H, d, J=8 Hz), 7.45 (1H, m), 7.61 (1H, d, J=9 Hz), 8.48 (1H, m), 8.66(1H, m)

Example 35N-[(2S)-5-(2-fluoro-6-methyl-3-pyridinyl)-2,3-dihydro-1H-inden-2-yl]-2-propanesulfonamide

To a solution ofN-[(2S)-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-2,3-dihydro-1H-inden-2-yl]-2-propanesulfonamide(250 mg, 0.68 mmol) in dry 1,4 dioxane (5 ml), polymer supportedPd(PPh₃)₄ (14 mg, 0.5 mmol/g, 0.007 mmol) was added along with3-bromo-2-fluoro-6-methylpyridine (194 mg, 1.02 mmol) and 680 μl of a 2MNa₂CO₃ solution in water. The resulting mixture was heated at 90°degrees for 3 hours. Then after cooling the resin was removed byfiltration and then the solvent was removed under reduced pressure. Theresidue was taken up with DCM, washed with water and loaded on a 25M+silica cartridge eluating with a cyclohexane/AcOEt 75/25 mixture. 175 mgof title compound were recovered as white solid (74%). Due to the use ofchiral Intermediate 7, the final compound is believed to beN-[(2S)-5-(2-fluoro-6-methyl-3-pyridinyl)-2,3-dihydro-1H-inden-2-yl]-2-propanesulfonamide.

Mass spectrum (ES): Found 349 (MH+), C₁₈H₂₁FN₂O₂S requires 348; ¹H-NMR(400 MHz, CDCl₃): 1.42 (6H, d, J=7 Hz), 2.55 (3H, s), 2.98 (2H, m), 3.21(1H, m), 3.39 (2H, m), 4.33 (2H, m), 7.11 (1H, d, J=8 Hz), 7.31 (1H, d,J=7 Hz), 7.37 (1H, d, J=8 Hz), 7.41 (1H, s), 7.73 (1H, m).

Example 36N-[(2S)-5-(2,6-difluoro-3-pyridinyl)-2,3-dihydro-1H-inden-2-yl]-2-propanesulfonamide

To a solution of (2,6-difluoro-3-pyridinyl)boronic acid (2 g, 12.56mmol) in dry 1,4 dioxane (30 ml), polymer supported Pd(PPh₃)₄ (126 mg,0.5 mmol/g, 0.063 mmol) was added along withN-[(2S)-5-bromo-2,3-dihydro-1H-inden-2-yl]-2-propanesulfonamide (2 g,6.28 mmol) and 7.3 ml of a 2M Na₂CO₃ solution in water and the resultingmixture was heated at 90° degrees for 3 hours. Then after cooling theresin was removed by filtration and then the solvent was removed underreduced pressure. The residue was taken up with AcOEt and water. Theaqueous phase was separated and acidified with 3N HCl and extracted withAcOEt. Then pH was reverted to basic by addition of NaHCO₃ and anotherextraction with AcOEt was performed. All the organic extracts werecollected, dried on Na₂SO₄, filtered and evaporated. The crude wasfinally purified on a 40M+ silica cartridge eluting with acyclohexane/AcOEt 80/20 mixture. 798 mg of title compound were recoveredas whitish solid (36%) Due to the use of the chiral Intermediate 6, thetitle compound is believed to beN-[(2S)-5-(2,6-difluoro-3-pyridinyl)-2,3-dihydro-1H-inden-2-yl]-2-propanesulfonamide.

Mass Spectrum (ES): Found 353 (MH+). C₁₇H₁₈F₂N₂O₂S requires 352. ¹H-NMR(500 MHz, DMSO-d6): δ 1.25 (6H, d, J=7 Hz), 2.90 (2H, m), 3.22 (3H, m),4.13 (1H, m), 7.27 (1H, d, J=7 Hz), 7.34 (2H, m), 7.41 (1H, m), 7.47(1H, d, J=8 Hz), 8.26 (1H, m)

Biological Assay

The ability of the compounds of the invention to potentiate glutamatereceptor-mediated response were determined a) by using fluorescentcalcium-indicator dyes such as FLUO4 and additionally for some examplecompounds, b) by measuring glutamate-evoked current recorded from humanGluR2 flip unedited HEK293 cells.

a) Calcium Influx Fluorescence Assay

384 well plates were prepared containing confluent monolayer of HEK 293cells either stably expressing or transiently transfected with humanGluR2 flip (unedited) AMPA receptor subunit. These cells form functionalhomotetrameric AMPA receptors. The tissue culture medium in the wellswas discarded and the wells were each washed three times with standardbuffer (80 μL) for the stable cell line (145 mM NaCl, 5 mM KCl, 1 mMMgCl₂, 2 mM CaCl₂, 20 mMN-[2-hydroxyethyl]-piperazine-N-[2-ethanesulfonic acid (HEPES), 5.5 mMglucose, pH 7.3) or with a Na-free buffer for the transient transfectedcells (145 mM N-methyl-glucamine instead of NaCl). The plates were thenincubated for 60 minutes in the dark with 2 μM FLUO4-AM dye (MolecularProbes, Netherlands) at room temperature to allow cell uptake of theFLUO-4AM, which is then converted to FLUO-4 by intracellular esteraseswhich is unable to leave the cell. After incubation each well was washedthree times with buffer (80 μL) (30 μL of buffer remained in each wellafter washing).

Compounds of the invention (or reference compounds such ascyclothiazide) were dissolved in dimethylsulfoxide (DMSO) at a stockconcentration of 10 mM. These solutions were further diluted with DMSOusing a Biomek FX (Beckman Coulter) in a 384 compound plate. Eachdilution (1 μL) was transferred to another compound plate and buffer (50μL) was added. An agonist stimulus (glutamate) plate was prepared bydissolving sodium glutamate in water to give a concentration of 100 mM.This solution was diluted with buffer to give a final concentration of500 μM and dispensed into another 384-well plate (50 μL/well) using aMultidrop (Thermolabsystems).

The cell plate was then transferred into a fluorescence imaging platebased reader [such as the FLIPR384 (Molecular Devices)]. A baselinefluorescence reading was taken over a 10 to 240 second period, and then10 μL from each plate containing a compound of the invention made up instandard buffer solution (in a concentration range from 100 μM to 10 pM)was added (to give a final concentration in the range 30 μM to 3 pM).The fluorescence was read over 5 minute period. 500 μM glutamatesolution (10 μL) was added (to give a final concentration of 100 μM).The fluorescence was then read over a 4 minute period. The activities ofthe compounds of the invention and reference compounds were determinedby measuring peak fluorescence after the last addition. The activity wasalso expressed relative to the fluorescence increase induced bycyclothiazide at their maximum response (i.e. greater than 30 μM).

All example compounds were screened using Assay a) and gave a pEC₅₀equal to or greater than 4.0 and demonstrated an activity at least 40%that of cyclothiazide (at their maximal responses). Some compounds gavea pEC₅₀ equal to or greater than 4.7. Example 4 gave a pEC₅₀ of 5.0.

b) Whole Cell Voltage-Clamp Electrophysiology Assay

This assay involved the electrophysiological characterisation of AMPAreceptor positive modulators using HEK293 cells stably expressing humanGluR2 flip (unedited) subunits which form a functional homotetramericAMPA receptor. The extracellular recording solution contained 135 mMNaCl, 2 mM KCl, 1 mM MgCl₂, 2 mM CaCl₂, 12 mMN-[2-hydroxyethyl]-piperazine-N-[2-ethanesulfonic acid (HEPES), 10 mMD-glucose, pH 7.35. The intracellular solution contained (150 mM CsCl,10 mM N-[2-hydroxyethyl]-piperazine-N-[2-ethanesulfonic acid (HEPES), 2mM ethylene glycol-bis(g-aminoethylether)-N,N,N′,N,-tetra-acetic acid(EGTA), pH 7.3. Intracellular solution containing amphotericin B (240μg/ml) was used to backfill the pipette while intracellular solutionalone was used to fill just the tip (the patch clamp pipettes have aresistance of between 2-5 MΩ). Amphoteracin B creates small pores in thecell membrane beneath the electrode which allow small ions to passacross the membrane (and therefore allow electrical control of the cell)without the dialysis of second messenger molecules out of the cell,which could result in metabolic rundown of the cell leading toinconsistent receptor activiton (Virginio C, Giacometti A, Aldegheri L,Rimland J M, Terstappen G C (2002) Eur J Pharmacol 445: 153-161) Themembrane potential of the cell was held at −60 mV and perforated-patchclamp electrophysiology performed using HEKA hard-and software(Germany). The cell was positioned in front of the first of 16 linearlyarranged channels. The system moves one channel then the next in frontof a single patch-clamped cell allowing rapid exchange and preciseapplication times of solutions (for more information seehttp://www.cellectricon.se/). The first channel contained normal bufferfor baseline current measurement. The second channel contained 3 mMglutamate which was applied to the cell for 500 ms to record a control(agonist alone) response. The third channel contained normal bufferwhich washed off glutamate for 1 to 3 min. The fourth channel containedeither a compound of the invention or a reference compound was moved infront of the cell for one minute. The fifth channel contained glutamatein the presence of the test (or reference) compound which was applied tothe cell for 500 ms. The sixth channel contained normal buffer whichwashed off the glutamate plus test (or reference) compound for 1 to 3min. This procedure was repeated for increasing concentrations of eithera compound of the invention or a reference compound. The activity of acompound of the invention is determined by measuring the peak currentamplitude or the area under the curve (500 ms) for the glutamateresponse in the presence of the compound of the invention (or reference)and expressing it as % of potentiation of the glutamate alone response(glutamate in the absence of the compound of the invention (or referencecompound). Alternatively, the activity can be expressed as the activityof glutamate in the presence of the compound of the invention (orreference compound) relative to the response induced by glutamate in thepresence of cyclothiazide at their maximal responses.

1. A compound of formula (I) or a pharmaceutically acceptable saltthereof:

wherein: R¹ is C₁₋₆alkyl, haloC₁₋₆alkyl, C₂₋₆alkenyl, amino,monoC₁₋₄alkylamino or diC₁₋₄alkylamino; R² and R³, are the same ordifferent and are hydrogen, halogen, C₁₋₆alkyl,haloC₁₋₆alkyl,C₁₋₄alkoxy, haloC₁₋₄alkoxy, cyano, amino,monoC₁₋₄alkylamino or diC₁₋₄alkylamino; each R⁴, which may be the sameor different, is C₁₋₆alkyl, halogen, haloC₁₋₆alkyl, C₁₋₄alkoxy,haloC₁₋₄alkoxy, cyano, nitro, amino, monoC₁₋₄alkylamino ordiC₁₋₄alkylamino; p is 0, 1 or 2; n is 1 or 2; R⁵ and R⁶, are the sameor different and are hydrogen, halogen, C₁₋₆alkyl, haloC₁₋₆alkyl,C₁₋₄alkoxy, haloC₁₋₄alkoxy, cyano, amino, monoC₁₋₄alkylamino ordiC₁₋₄alkylamino; and Het is thienyl, pyridyl, pyrimidinyl, pyridazinyl,pyrazinyl, imidazolyl, pyrazolyl, pyrrolyl, quinolyl, thiazolyl orfuryl, each of which may be substituted by one or more groupsindependently selected from the group consisting of C₁₋₆alkyl,C₁₋₆alkoxy, acetyl, halogen, haloC₁₋₆alkyl, cyano, nitro, amino,monoC₁₋₄alkylamino and diC₁₋₄alkylamino.
 2. A compound or salt asclaimed in claim 1 wherein R¹ is C₁₋₆alkyl.
 3. A compound or salt asclaimed in claim 1 wherein R² and R³ are the same or different and arehydrogen, halogen or C₁₋₆alkyl.
 4. A compound or salt according to claim1 wherein p is
 0. 5. A compound or salt according to claim 1 whereineach R⁴, which may be the same or different, is C₁₋₆alkyl or halogen. 6.A compound or salt according to claim 1 wherein R⁵ and R⁶, which may bethe same or different, are hydrogen, halogen or C₁₋₆alkyl.
 7. A compoundor salt according to claim 1 wherein n is
 1. 8. A compound or saltaccording to claim 1 wherein Het is 3-pyridyl, 5-pyrimidinyl,2-pyrimidinyl, 3-thienyl, 2-thienyl, 3-pyridazinyl, 1H-4-imidazolyl or1H-4-pyrazolyl; each of which is unsubstituted or substituted by one tothree groups independently selected from the group consisting ofC₁₋₆alkyl, acetyl, cyano, halogen, haloC₁₋₆alkyl and C₁₋₆alkoxy.
 9. Acompound or salt according to claim 8 wherein the Het group issubstituted by one to three groups independently selected from the groupconsisting of methyl, acetyl, cyano, fluorine, CF₃ and methoxy.
 10. Acompound as claimed in claim 1 having a formula (Ib) or apharmaceutically acceptable salt thereof:

wherein R¹, R², R³, R⁴, R⁵, R⁶, n, p, and Het are the same as inclaim
 1. 11. A compound as claimed in claim 10 having a formula (Ic) ora pharmaceutically acceptable salt thereof:

wherein Het and R¹ are as defined in claim
 10. 12. A compound or salt asclaimed in claim 11 wherein R¹ is C₁₋₆alkyl.
 13. A compound or salt asclaimed in claim 11 wherein R² and R³ are the same or different and arehydrogen, halogen or C₁₋₆alkyl.
 14. A compound or salt according toclaim 11 wherein p is
 0. 15. A compound or salt according to claim 11wherein each R⁴, which may be the same or different, is C₁₋₆alkyl orhalogen.
 16. A compound or salt according to claim 11 wherein R⁵ and R⁶,which may be the same or different, are hydrogen, halogen or C₁₋₆alkyl.17. A compound or salt according to claim 11 wherein n is
 1. 18. Acompound or salt according to claim 11 wherein Het is 3-pyridyl,5-pyrimidinyl, 2-pyrimidinyl, 3-thienyl, 2-thienyl, 3-pyridazinyl,1H-4-imidazolyl or 1H-4-pyrazolyl; each of which is unsubstituted orsubstituted by one to three groups independently selected from the groupconsisting of C₁₋₆alkyl, acetyl, cyano, halogen, haloC₁₋₆alkyl andC₁₋₆alkoxy.
 19. A compound or salt according to claim 18 wherein the Hetgroup is substituted by one to three groups independently selected fromthe group consisting of methyl, acetyl, cyano, fluorine, CF₃ andmethoxy.
 20. A compound (Id) or a salt thereof according to claim 1which is

wherein R¹, R², R³, R⁴, R⁵, R⁶, n, p, and Het are as defined in claim 1.21. A compound or salt as claimed in claim 20 wherein R¹ is C₁₋₆alkyl.22. A compound or salt as claimed in claim 20 wherein R² and R³ are thesame or different and are hydrogen, halogen or C₁₋₆alkyl.
 23. A compoundor salt according to claim 20 wherein p is
 0. 24. A compound or saltaccording to claim 20 wherein each R⁴, which may be the same ordifferent, is C₁₋₆alkyl or halogen.
 25. A compound or salt according toclaim 20 wherein R⁵ and R⁶, which may be the same or different, arehydrogen, halogen or C₁₋₆alkyl.
 26. A compound or salt according toclaim 20 wherein n is
 1. 27. A compound or salt according to claim 20wherein Het is 3-pyridyl, 5-pyrimidinyl, 2-pyrimidinyl, 3-thienyl,2-thienyl, 3-pyridazinyl, 1H-4-imidazolyl or 1H-4-pyrazolyl; each ofwhich is unsubstituted or substituted by one to three groupsindependently selected from the group consisting of C₁₋₆alkyl, acetyl,cyano, halogen, haloC₁₋₆alkyl and C₁₋₆alkoxy.
 28. A compound or saltaccording to claim 27 wherein the Het group is substituted by one tothree groups independently selected from the group consisting of methyl,acetyl, cyano, fluorine, CF₃ and methoxy.
 29. A compound or saltaccording to claim 1, which is:N-[5-(2-fluoro-3-pyridinyl)-2,3-dihydro-1H-inden-2-yl]-2-propanesulfonamide;N-[5-(5-pyrimidinyl)-2,3-dihydro-1H-inden-2-yl]-2-propanesulfonamide;N-[5-(3-thienyl)-2,3-dihydro-1H-inden-2-yl]-2-propanesulfonamide;N-[5-(3-pyridinyl)-2,3-dihydro-1H-inden-2-yl]-2-propanesulfonamide;N-[5-(2-thienyl)-2,3-dihydro-1H-inden-2-yl]-2-propanesulfonamide;N-[5-(4-methyl-3-pyridinyl)-2,3-dihydro-1H-inden-2-yl]-2-propanesulfonamide;N-[5-(2,6-dimethyl-3-pyridinyl)-2,3-dihydro-1H-inden-2-yl]-2-propanesulfonamide;N-[5-(6-cyano-3-pyridinyl)-2,3-dihydro-1H-inden-2-yl]-2-propanesulfonamide;N-[5-(5-acetyl-3-pyridinyl)-2,3-dihydro-1H-inden-2-yl]-2-propanesulfonamide;N-[5-(5-cyano-3-pyridinyl)-2,3-dihydro-1H-inden-2-yl]-2-propanesulfonamide;N-[5-(5-fluoro-2-pyridinyl)-2,3-dihydro-1H-inden-2-yl]-2-propanesulfonamide;N-[5-(4-pyridinyl)-2,3-dihydro-1H-inden-2-yl]-2-propanesulfonamide;N-[5-(2-pyridinyl)-2,3-dihydro-1H-inden-2-yl]-2-propanesulfonamide;N-[5-(6-fluoro-2-pyridinyl)-2,3-dihydro-1H-inden-2-yl]-2-propanesulfonamide;N-[5-(2-methyl-4-pyridinyl)-2,3-dihydro-1H-inden-2-yl]-2-propanesulfonamide;N-[5-(6-methyl-3-pyridazinyl)-2,3-dihydro-1H-inden-2-yl]-2-propanesulfonamide;N-[5-(2-pyrimidinyl)-2,3-dihydro-1H-inden-2-yl]-2-propanesulfonamide;N-[5-(3-fluoro-4-pyridinyl)-2,3-dihydro-1H-inden-2-yl]-2-propanesulfonamide;N-[5-(6-fluoro-2-methyl-3-pyridinyl)-2,3-dihydro-1H-inden-2-yl]-2-propanesulfonamide;N-[5-(1H-imidazol-4-yl)-2,3-dihydro-1H-inden-2-yl]-2-propanesulfonamideN-[5-(1,3,5-trimethyl-1H-pyrazol-4-yl)-2,3-dihydro-1H-inden-2-yl]-2-propanesulfonamide;N-[5-(6-methyl-3-pyridinyl)-2,3-dihydro-1H-inden-2-yl]-2-propanesulfonamide;N-[5-(3-methyl-2-pyridinyl)-2,3-dihydro-1H-inden-2-yl]-2-propanesulfonamide;N-[5-(5-methyl-2-pyridinyl)-2,3-dihydro-1H-inden-2-yl]-2-propanesulfonamide;N-[5-(6-chloro-3-pyridinyl)-2,3-dihydro-1H-inden-2-yl]-2-propanesulfonamide;N-{5-[6-(methyloxy)-3-pyridinyl]-2,3-dihydro-1H-inden-2-yl}-2-propanesulfonamide;N-[5-(5-chloro-2-pyridinyl)-2,3-dihydro-1H-inden-2-yl]-2-propanesulfonamide;N-[5-(2-chloro-3-pyridinyl)-2,3-dihydro-1H-inden-2-yl]-2-propanesulfonamide;N-{(2S)-5-[6-(trifluoromethyl)-3-pyridinyl]-2,3-dihydro-1H-inden-2-yl}-2-propanesulfonamide;N-[(2S)-5-(5-chloro-2-pyridinyl)-2,3-dihydro-1H-inden-2-yl]-2-propanesulfonamide;N-{(2S)-5-[6-(trifluoromethyl)-2-pyridinyl]-2,3-dihydro-1H-inden-2-yl}-2-propanesulfonamide;N-[(2S)-5-(5-methyl-3-pyridinyl)-2,3-dihydro-1H-inden-2-yl]-2-propanesulfonamide;N-[(2S)-5-(5-fluoro-3-pyridinyl)-2,3-dihydro-1H-inden-2-yl]-2-propanesulfonamide;N-[(2S)-5-(2-fluoro-6-methyl-3-pyridinyl)-2,3-dihydro-1H-inden-2-yl]-2-propanesulfonamide;N-[(2S)-5-(2,6-difluoro-3-pyridinyl)-2,3-dihydro-1H-inden-2-yl]-2-propanesulfonamide;or an S or R isomer thereof; or a pharmaceutically acceptable saltthereof.
 30. A pharmaceutical composition comprising a compoundaccording to claim 1 and a pharmaceutically acceptable carrier ordiluent.
 31. A pharmaceutical composition according to claim 30 whereinthe compound or its salt is enriched in the R or the S isomer.
 32. Amethod for treating schizophrenia comprising administering to a human inneed thereof, a compound of Formula (I) according to claim 1 alone oradmixed with a pharmaceutically acceptable carrier.